Overview
Cluster Headache
1. Clinical Overview
Summary
Cluster headache is a primary headache disorder and the most severe of the trigeminal autonomic cephalalgias (TACs). It is characterized by excruciating, strictly unilateral pain localised to the orbital, supraorbital, or temporal region, lasting 15-180 minutes and occurring up to 8 times daily. Attacks are accompanied by ipsilateral cranial autonomic features: conjunctival injection, lacrimation, nasal congestion, ptosis, and miosis. Unlike migraine, patients are typically restless and agitated during attacks. The name derives from the temporal clustering of attacks — episodes occur daily for weeks to months (a "cluster period") followed by remission. Cluster headache is sometimes called "suicide headache" due to the intensity of pain. First-line acute treatment is high-flow oxygen or subcutaneous sumatriptan; verapamil is first-line for prevention.
Key Facts
- Definition: Primary headache disorder; part of trigeminal autonomic cephalalgias (TACs)
- Prevalence: 0.1% of the population (relatively rare)
- Sex ratio: Male:Female 3:1 (historically 6:1, narrowing)
- Pain severity: Described as "worst pain imaginable"; 10/10
- Attack duration: 15-180 minutes (typically 45-90 minutes)
- Attack frequency: 1-8 per day during cluster period
- Key treatment: High-flow oxygen (100%, 12-15 L/min) aborts attack in 15 minutes
- Prevention: Verapamil (first-line prophylaxis)
Clinical Pearls
Behaviour = Diagnosis: Migraine patients lie still in a dark room. Cluster headache patients are restless, agitated, pacing, or rocking. This behavioural difference is a key clinical discriminator.
The Alarm Clock Headache: Cluster attacks often occur at the same time each night, frequently 1-2 hours after falling asleep — linked to REM sleep and hypothalamic circadian regulation.
Alcohol is the Trigger: During a cluster period, even small amounts of alcohol reliably trigger an attack within 30-60 minutes. Patients learn to avoid alcohol completely during clusters.
Why This Matters Clinically
Cluster headache causes extreme suffering and is frequently misdiagnosed (average delay to diagnosis: 5-7 years). The severity of pain leads to significant risk of suicidal ideation — screening is essential. However, with correct diagnosis, treatment is highly effective. High-flow oxygen is a simple, safe intervention that can abort attacks within minutes.
2. Epidemiology
Incidence & Prevalence
- Prevalence: 0.1% (1 in 1000)
- Incidence: 10-15 per 100,000 per year
- Peak onset age: 20-40 years
- Trend: Stable; possible increase in female prevalence
Demographics
| Factor | Details |
|---|---|
| Age | Onset typically 20-40 years (rare before puberty or after 60) |
| Sex | Male:Female 3:1 (historically higher; now narrowing) |
| Ethnicity | All ethnic groups; no clear variation |
| Geography | Worldwide distribution |
Risk Factors
Non-Modifiable:
- Male sex
- Family history of cluster headache (5-20x increased risk in first-degree relatives)
- Blue eye colour (possible association)
Modifiable:
| Risk Factor | Association |
|---|---|
| Smoking | 65-80% of cluster headache patients are smokers |
| Heavy alcohol use | Association (but causality unclear) |
| Head trauma | Possible trigger in susceptible individuals |
3. Pathophysiology
Mechanism
Step 1: Hypothalamic Activation (The Pacemaker)
- PET studies show activation of ipsilateral posterior hypothalamus during attacks
- Hypothalamus acts as "cluster generator" — explains circadian rhythmicity
- Links to REM sleep (attacks often occur 1-2 hours after sleep onset)
Step 2: Trigeminal-Autonomic Reflex Activation
- Trigeminal nerve (V1 — ophthalmic division) mediates the pain
- Parasympathetic outflow via facial nerve causes autonomic features
- Trigeminal-autonomic reflex is activated in ipsilateral pathway
Step 3: Calcitonin Gene-Related Peptide (CGRP) Release
- CGRP and vasoactive intestinal peptide (VIP) released during attacks
- Cause vasodilation and neurogenic inflammation
- CGRP monoclonal antibodies now used for prevention (galcanezumab)
Step 4: Pain and Autonomic Symptoms
- Severe pain in V1 distribution (orbital, supraorbital, temporal)
- Ipsilateral autonomic features from parasympathetic activation:
- Conjunctival injection and lacrimation
- Nasal congestion/rhinorrhoea
- Eyelid oedema
- Ptosis and miosis (partial Horner syndrome — due to carotid wall oedema)
Classification
By Temporal Pattern:
| Type | Definition | Prevalence |
|---|---|---|
| Episodic | Cluster periods lasting 7 days - 1 year, separated by remissions ≥3 months | 80-90% |
| Chronic | Attacks for ≥1 year without remission, or remission less than 3 months | 10-20% |
Trigeminal Autonomic Cephalalgias (TACs) Comparison:
| Feature | Cluster Headache | Paroxysmal Hemicrania | SUNCT/SUNA | Hemicrania Continua |
|---|---|---|---|---|
| Duration | 15-180 min | 2-30 min | 1-600 sec | Continuous |
| Frequency | 1-8/day | 5-40+/day | 3-200/day | Continuous + exacerbations |
| Treatment | Oxygen, triptans, verapamil | Indomethacin (absolute response) | Lamotrigine | Indomethacin |
Anatomical Considerations
- Pain localises to trigeminal V1 distribution
- Autonomic features reflect parasympathetic activation via superior salivatory nucleus
- Partial Horner syndrome (ptosis, miosis, but NOT anhidrosis) — due to internal carotid sympathetic plexus involvement
117. Deep Dive: The Hypothalamic Pacemaker
"The Clock in the Brain."
- Circadian & Circannual: The strict timing of attacks (e.g. 2am every night) implicates the Suprachiasmatic Nucleus (SCN) of the hypothalamus.
- Melatonin: Cluster patients have blunted nocturnal melatonin secretion.
- Testosterone: Levels are often lower during a bout.
- Neuroimaging: PET scans show specific activation of the posterior inferior hypothalamus during an attack. This area is NOT active in migraine.
- The Switch: It seems the hypothalamus activates the trigeminal system, which then releases CGRP. The pain is the "siren", but the hypothalamus is the "hand pulling the lever".
118. Case Studies
Case A: The "Sinus" Misdiagnosis.
- 30-year-old male. Recurring "Sinus Headaches" every Spring.
- Pain around right eye and nose. Nose runs. Eye waters.
- Treated with antibiotics and nasal sprays for 5 years.
- referred to ENT for "Septoplasty".
- ENT notes: "Pain is 10/10 and lasts 45 mins. He pace around the room."
- Diagnosis: Cluster Headache.
- Treatment: Verapamil + Oxygen. Remission achieved.
Case B: The Chronic Sufferer.
- 45-year-old female. Chronic Cluster for 10 years.
- Attacks 5 times a day. No remission.
- Failed Verapamil (heart block), Lithium (toxicity), Topiramate.
- Suicidal ideation prominent.
- Intervention: Occipital Nerve Stimulation (ONS) implant.
- Outcome: 50% reduction in attack frequency. Quality of life restored.
4. Clinical Presentation
Symptoms
Pain Characteristics:
Temporal Pattern:
Triggers (During Cluster Period):
Signs (During Attack)
Ipsilateral Autonomic Features (Cranial Parasympathetic):
Behavioural Signs:
Red Flags
[!CAUTION] Red Flags — Exclude secondary causes if:
- First ever attack (needs imaging to exclude mass, aneurysm)
- Atypical features (bilateral pain, posterior headache, duration greater than 3 hours)
- Neurological deficit (weakness, sensory change, visual loss)
- Onset after age 50 (consider giant cell arteritis, mass)
- Progressive worsening over time
- Lack of response to typical treatments
- Systemic symptoms (fever, weight loss)
Excruciating severity (10/10 — "worst pain ever experienced")
Common presentation.
Strictly unilateral (does not change sides within cluster period)
Common presentation.
Location
orbital, supraorbital, temporal (sometimes cheek, jaw)
Duration
15-180 minutes (typically 45-90 min)
Frequency
1-8 attacks per day
5. Clinical Examination
Structured Approach
During Attack:
- Patient is restless, pacing, cannot lie still
- Ipsilateral eye: injected, watering
- Nose: blocked or running on same side
- Eyelid: oedema, ptosis
- Pupil: miosis (compare to opposite side)
Between Attacks:
- Neurological examination: NORMAL (any deficit requires imaging)
- Partial Horner syndrome may persist in some chronic cases
- General examination usually unremarkable
Special Tests
| Test | Technique | Positive Finding | Clinical Significance |
|---|---|---|---|
| Pupil comparison | Compare in dim light | Ipsilateral miosis | Partial Horner syndrome |
| Ptosis assessment | Observe palpebral fissure | Mild drooping | Partial Horner during attack |
| Indomethacin trial | 75-150mg daily × 3 days | Relief of attacks | Suggests paroxysmal hemicrania, NOT cluster |
| Greater occipital nerve tenderness | Palpate over occipital nerve | Tender | May respond to nerve block |
6. Investigations
First-Line (Bedside)
- Clinical diagnosis — Based on ICHD-3 criteria
- Oxygen trial — Therapeutic trial; relief supports diagnosis
- Vital signs — Rule out hypertensive emergency
Laboratory Tests
| Test | Expected Finding | Purpose |
|---|---|---|
| ESR and CRP | Normal | Exclude GCA if age greater than 50 |
| TFTs | Normal | Baseline before lithium if considered |
| U&Es | Normal | Baseline before lithium |
| LFTs | Normal | Baseline if long-term therapy planned |
Imaging
| Modality | Findings | Indication |
|---|---|---|
| MRI brain with pituitary views | Normal in primary cluster; rules out pituitary lesion, posterior fossa mass | First presentation; atypical features |
| MRA | Normal | If concern for aneurysm, carotid dissection |
| CT head | Usually normal; may miss subtle lesions | Emergency if concerning red flags |
Diagnostic Criteria
ICHD-3 Criteria for Cluster Headache:
A. At least 5 attacks fulfilling criteria B-D B. Severe or very severe unilateral orbital, supraorbital, and/or temporal pain lasting 15-180 minutes untreated C. Either or both of the following:
- At least one ipsilateral autonomic symptom:
- Conjunctival injection and/or lacrimation
- Nasal congestion and/or rhinorrhoea
- Eyelid oedema
- Forehead and facial sweating
- Miosis and/or ptosis
- A sense of restlessness or agitation D. Frequency: 1-8 attacks per day for more than half the time when active E. Not better accounted for by another ICHD-3 diagnosis
7. Management
Management Algorithm
Acute Attack Treatment
First-Line: High-Flow Oxygen
- 100% oxygen at 12-15 L/min
- Delivered via non-rebreather mask with reservoir bag
- Duration: 15-20 minutes
- Effective in 70-80% within 15 minutes
- Safe, no limits on use, no contraindications except fire risk
- Patients should be prescribed home oxygen
Second-Line: Triptans (Parenteral or Nasal)
| Drug | Dose | Route | Onset | Key Points |
|---|---|---|---|---|
| Sumatriptan | 6mg | Subcutaneous | 5-10 min | Most effective; max 2 doses/24h |
| Sumatriptan | 20mg | Nasal spray | 15-20 min | Alternative to SC |
| Zolmitriptan | 5mg | Nasal spray | 15-20 min | Alternative |
NOT recommended:
- Oral triptans (too slow onset — attack typically over before effect)
- Paracetamol, NSAIDs (ineffective)
- Opioids (ineffective and habituation risk)
Preventive (Prophylactic) Treatment
Transitional (Short-term Bridge):
| Drug | Dose | Duration | Notes |
|---|---|---|---|
| Prednisolone | 60-80mg daily, taper over 2-3 weeks | 2-3 weeks | Rapid onset; use while titrating verapamil |
| Greater occipital nerve block | Steroid + local anaesthetic | Single injection | Can provide 2-4 weeks relief |
Maintenance Prophylaxis:
| Drug | Dose | Key Points |
|---|---|---|
| Verapamil | 240-960mg daily in divided doses | First-line; ECG before and with each dose increase (risk of heart block) |
| Lithium | 600-1200mg daily (levels 0.6-1.0 mmol/L) | Second-line; monitoring of levels, TFTs, U&Es required |
| Topiramate | 100-200mg daily | Alternative; weight loss, cognitive side effects |
| Melatonin | 10-25mg nocte | Adjunctive; may help regulate circadian rhythm |
Newer Therapies (Specialist):
- Galcanezumab (CGRP monoclonal antibody) — Now licensed for episodic cluster headache prophylaxis
- Sphenopalatine ganglion stimulation — Implantable device for refractory cases
- Occipital nerve stimulation — For chronic refractory cases
Disposition
- Primary care management: Established diagnosis with effective acute treatment
- Specialist referral: First presentation; refractory to standard treatment; chronic type
- Emergency department: Acute severe attack; suicidal ideation; diagnostic uncertainty
- Follow-up: Every 3-6 months during cluster period; annual if in remission
8. Deep Dive: Oxygen Therapy Protocol
"The Purest Drug". High-Flow Oxygen is the gold standard for aborting cluster attacks. It is under-prescribed due to logistical hurdles.
- Mechanism: Vasoconstriction of cerebral vessels? Inhibition of trigeminal activation? Exact mechanism unknown.
- The Prescription:
- Flow Rate: 12-15 Litres/minute (Must be high flow).
- Mask: Non-Rebreather (Reservation bag must be full).
- Duration: 15-20 minutes.
- Post-Attack: Continue for 5 mins after pain stops (prevent rebound).
- Efficacy: Stops pain in ~78% of patients within 15 mins.
- Advantages: No side effects. Can be used for every attack (unlike Triptans). Safe in pregnancy/CVD.
9. Technical Appendix: Verapamil Safety
Monitoring the Heart while saving the Head. Verapamil is a calcium channel blocker used at high doses (up to 960mg) for Cluster Headache. This risks heart block.
- The Protocol:
- Baseline ECG: Essential. Check PR interval.
- Start Dose: 80mg TDS (240mg daily).
- Titration: Increase by 80mg every 2 weeks.
- Monitoring: Perform ECG 10 days after every dose increment.
- Stop/Reduce if:
- PR interval > 0.20s (First degree block).
- Bradycardia < 50 bpm.
- Hypotension.
10. Rehabilitation: Living with "Suicide Headache"
The Psychological Toll.
- Suicide Risk: 55% of patients have suicidal ideation. 2% attempt. The risk is driven by pain severity and fear of the next attack.
- PTSD: Patients develop PTSD-like symptoms (avoidance, hyperarousal) regarding the attacks.
- Family Impact: Partners witness the patient screaming, banging their head, or mutilating themselves during attacks.
- Support: OUCH (Organization for the Understanding of Cluster Headache) provides vital peer support. Referral to pain psychology is often needed.
Management of Refractory Cases (Surgical Atlas)
When meds fail.
- Greater Occipital Nerve Block: Methylprednisolone + Lidocaine. Relief for 2-4 weeks.
- Sphenopalatine Ganglion Stimulation: Implantable device (Pulsante).
- Occipital Nerve Stimulation: Implanted electrodes.
- Deep Brain Stimulation (DBS): Posterior Hypothalamus. Last resort.
11. Disposition
(Renumbered)
8. Complications
Immediate (During Attack)
| Complication | Incidence | Presentation | Management |
|---|---|---|---|
| Suicidal ideation | 30-50% have considered | Desperation due to pain | Safety assessment, psychiatric support |
| Self-harm during attack | Rare | Hitting head, injuring self | Supervision, effective treatment |
Early (During Cluster Period)
- Sleep deprivation: Due to nocturnal attacks
- Depression and anxiety: Common comorbidity
- Work absence: Significant functional impairment
- Medication overuse: From triptan overuse (risk of MOH)
Late (Chronic)
- Chronic cluster headache: 10-20% become chronic (no significant remission)
- Social isolation: Due to fear of attacks
- Relationship strain: Impact on family and work
- Secondary psychological disorders: Anxiety, depression, PTSD-like symptoms
9. Prognosis & Outcomes
Natural History
- Episodic type: Cluster periods (weeks-months) with remissions (months-years)
- May transition from episodic to chronic (10-15%) or vice versa
- Attacks may reduce in frequency with age (especially after age 60)
- Some patients experience spontaneous remission
Outcomes with Treatment
| Variable | Outcome |
|---|---|
| Oxygen effectiveness | 70-80% abort attack within 15 min |
| SC sumatriptan effectiveness | 75-90% respond |
| Verapamil prophylaxis | 50-70% reduction in attacks |
| Complete remission (long-term) | Variable; some lifelong, some remit |
Prognostic Factors
Good Prognosis:
- Episodic type (vs chronic)
- Younger age at onset
- Clear remission periods
- Good response to oxygen/triptans
- Engagement with specialist headache service
Poor Prognosis:
- Chronic subtype
- Older age at onset
- Smoking (continued)
- Transition from episodic to chronic
- Medication overuse
- Comorbid depression
10. Evidence & Guidelines
Key Guidelines
- BASH (British Association for the Study of Headache) Guidelines (2019) — Cluster headache management. Recommends high-flow oxygen first-line. BASH
- European Headache Federation Guideline (2016) — Management of trigeminal autonomic cephalalgias. EHF
- NICE CKS (Clinical Knowledge Summaries) — Headache - cluster. Primary care guidance. NICE CKS
Landmark Trials
Cohen et al. (2009) — High-flow oxygen for cluster headache
- 76 patients randomised to oxygen vs air
- Key finding: Oxygen was significantly superior (78% vs 20% pain-free at 15 min)
- Clinical Impact: Confirmed high-flow oxygen as first-line acute treatment
Goadsby et al. (2019) — Galcanezumab for episodic cluster headache
- 106 patients randomised to galcanezumab vs placebo
- Key finding: Galcanezumab reduced weekly attacks by 8.7 vs 5.2 (placebo)
- Clinical Impact: First CGRP antibody licensed for cluster headache prophylaxis
Leone et al. (Multiple Studies) — Verapamil efficacy
- Open-label and observational studies
- Key finding: Verapamil effective prophylaxis but high doses required (often 480-960mg)
- Clinical Impact: Established verapamil as first-line preventive
Evidence Strength
| Intervention | Level | Key Evidence |
|---|---|---|
| High-flow oxygen | 1b | Cohen et al. RCT |
| SC sumatriptan | 1a | Multiple RCTs |
| Verapamil prophylaxis | 2a | Observational studies; consensus |
| Galcanezumab | 1b | Goadsby RCT |
| Greater occipital nerve block | 2a | Open-label studies |
13. Examination Focus
Common Exam Questions
1. MRCP / PLAB:
- Q: A 30-year-old male presents with severe right-sided orbital pain, lasting 45 minutes, occurring 3 times a day for 2 weeks. His right eye is red and watering. What is the acute treatment?
- A: High-Flow Oxygen (100%) or SC Sumatriptan. (Oral triptans are wrong - too slow).
2. Neurology Rotation:
- Q: What is the most specific physical sign of Cluster Headache during an attack?
- A: Ipsilateral Autonomic Features (Ptosis, Miosis, Lacrimation, Conjunctival Injection).
3. Safety:
- Q: You plan to start Verapamil for Cluster prophylaxis. What investigation is mandatory?
- A: ECG. To check for Heart Block (PR prolongation). Verapamil causes bradycardia/block.
Viva Points
- Horner's Syndrome: Why do they get it? The sympathetic plexus around the Internal Carotid Artery is compressed by the swollen vessel wall involved in the attack. It is often a "partial" Horner's (Ptosis/Miosis without Anhidrosis).
- The Agitated Patient: Contrast with Migraine (Still). Cluster patients PACE.
- Alcohol Trigger: Patognomonic feature. "Do you avoid a pint during a bout?" -> "Yes, it sets it off immediately."
11. Patient/Layperson Explanation
What is Cluster Headache?
Cluster headache is one of the most painful conditions known to medicine — some people call it "suicide headache" because the pain is so severe. It causes intense, one-sided pain around or behind your eye that can last from 15 minutes to 3 hours. Unlike migraines, where people lie still, cluster headache makes you feel restless — you might pace around or even bang your head against the wall.
The headaches come in "clusters" — meaning you might have 1-8 attacks a day for several weeks or months, then no headaches at all for months or even years.
Is it serious?
The pain is extremely severe, but cluster headache is not caused by anything dangerous in the brain. However, the pain is so intense that some people feel hopeless or even suicidal during attacks. If you ever feel this way, please tell your doctor immediately — there are treatments that work.
How is it treated?
- Oxygen: Breathing 100% oxygen through a mask for 15-20 minutes is one of the best treatments. It can stop an attack in about 15 minutes. Your doctor can arrange for you to have oxygen at home.
- Sumatriptan injection: A self-administered injection under the skin works within 5-10 minutes. This is the fastest medication option.
- Preventive medication: To stop attacks from happening, you may take verapamil (a heart medication used off-label). This requires regular heart tracings (ECGs) while the dose is increased.
- Avoid alcohol: During a cluster period, even a small amount of alcohol can trigger an attack within the hour.
What to expect
- Attacks typically occur at the same time each day, often at night
- The cluster period usually lasts 2-12 weeks
- Most people have long periods of remission between clusters
- Treatment is very effective — the key is getting the right diagnosis
When to seek help
See a doctor urgently if:
- This is your first ever attack of this type of headache
- You have weakness, numbness, or visual changes
- The headache is different from your usual cluster headaches
- You are feeling hopeless or have thoughts of harming yourself
- Your usual treatment is not working
12. References
Primary Guidelines
- British Association for the Study of Headache. Guidelines for all healthcare professionals in the diagnosis and management of cluster headache. 2019. BASH
- May A, et al. Cluster headache. Nat Rev Dis Primers. 2018;4:18006. PMID: 29542085
Key Trials
- Cohen AS, et al. High-flow oxygen for treatment of cluster headache: a randomized trial. JAMA. 2009;302(22):2451-2457. PMID: 19996398
- Goadsby PJ, et al. Trial of Galcanezumab in Prevention of Episodic Cluster Headache. N Engl J Med. 2019;381(2):132-141. PMID: 31291515
- The Sumatriptan Cluster Headache Study Group. Treatment of acute cluster headache with sumatriptan. N Engl J Med. 1991;325(5):322-326. PMID: 1647496
- Leone M, et al. Verapamil in the prophylaxis of episodic cluster headache: a double-blind study versus placebo. Neurology. 2000;54(6):1382-1385. PMID: 10746617
Further Resources
- OUCH UK (Organisation for the Understanding of Cluster Headache): ouchuk.org
- The Migraine Trust: migrainetrust.org
- Clusterbusters (Patient Advocacy): clusterbusters.org
119. Deep Dive: Oxygen Logistics
"Why is it so hard to get?"
- The Prescription: Most GPs cannot prescribe "High Flow Oxygen" easily (it's specialized).
- The Equipment: Patients need a High Concentration Non-Rebreathing Mask (Reservoir bag) and a cylinder with a High Flow Regulator (Must deliver >12-15 L/min). Standard COPD flow rates (2 L/min) are useless.
- The Demand Valve: Some patients prefer a "Demand Valve" (like scuba diving) which delivers oxygen only on inspiration. It is more effective but harder to fund.
120. Case Studies (Continued)
Case C: The Episodic -> Chronic Transition.
- 50-year-old male. Had episodic cluster for 20 years (bouts every Autumn).
- Last year, the bout didn't stop.
- Now has daily attacks for 18 months.
- This transition (Secondary Chronic) is difficult to treat.
- Response to Lithium was poor.
- Considered for Gammacore (nVNS).
13. Surgical Atlas: Neuromodulation (Expanded)
(Renumbered)
"Hacking the Nerve." When drugs fail, we turn to electricity.
- Non-Invasive Vagus Nerve Stimulation (nVNS - gammaCore):
- Handheld device held against the neck.
- Stimulates the Vagus nerve.
- Mechanism: Modulates pain pathways via the Nucleus Tractus Solitarius.
- Evidence: Approved for acute and preventive treatment. Safe (no surgery). Cost is the barrier.
- Sphenopalatine Ganglion (SPG) Stimulation:
- The SPG is the major parasympathetic ganglion ("The Autonomic Hub").
- Pulsante Device: Implanted via the gum (maxilla).
- Patient holds a remote to the cheek during an attack to stimulate the ganglion.
- Effect: Blocks the autonomic outflow, stopping the lacrimation/congestion and often the pain.
14. Ethics: The Suicide Headache
"Intervening in Despair."
- The Reality: Cluster headache has a high rate of suicide during attacks (impulsive) and between attacks (dread).
- The Physician's Duty:
- Acknolwedgement: Validating the pain ("I know it is 10/10") is therapeutic.
- Access: Ensuring they have Oxygen. Oxygen is life-saving because it gives the patient control.
- Safety: If a patient is chronic and failing meds, admission for IV Dihydroergotamine (DHE) or high-dose steroids to break the cycle is justified to prevent suicide.
Medical Disclaimer: MedVellum content is for educational purposes and clinical reference. If you are experiencing thoughts of suicide or self-harm, please seek immediate help from a healthcare professional or emergency services.