Overview
Hemicrania continua is a rare but distinct type of chronic headache disorder. The name means 'continuous one-sided headache' in Latin, which describes its most defining feature: a constant, unrelenting headache that stays on one side of the head — always the same side — without switching. The pain is present every day, all day, and never fully goes away, though it can get worse in flares. During these flares, people often experience additional symptoms on the same side as the headache, such as a red or watery eye, a drooping eyelid, a stuffy or runny nose, or a feeling of restlessness and agitation. Hemicrania continua belongs to a group of headaches called 'trigeminal autonomic cephalalgias,' which involve both head pain and automatic nervous system responses in the face. What makes this condition especially important to identify correctly is that it responds almost completely to a single medication called indomethacin, a type of anti-inflammatory drug. This dramatic response to indomethacin is actually used as part of the diagnosis. Without the right diagnosis, people can suffer for years without relief. The condition can affect people of any age, though it most often begins in adulthood. It is considered a rare disorder, but it may be underdiagnosed because it can be mistaken for migraine, cluster headache, or other chronic daily headache conditions. With proper diagnosis and treatment, most people experience significant relief.
Key symptoms:
Constant one-sided headache that never fully goes awayHeadache always stays on the same side of the headPeriods of worsening pain (flares) on top of the baseline headacheRed or bloodshot eye on the side of the headacheWatery or tearing eye on the affected sideDrooping or swollen eyelid on the affected sideStuffy or runny nose on the affected sideFeeling of restlessness or agitation during flaresSensitivity to light or sound during flaresThrobbing or stabbing pain during flare-upsFeeling of pressure or tightness in the head
Sporadic
Usually appears on its own, not inherited from a parent
Adult
Begins in adulthood (age 18 or older)
FDA & Trial Timeline
2 eventsThe University of Texas Health Science Center, Houston — PHASE1
Data sourced from FDA regulatory filings and ClinicalTrials.gov. Updated periodically.
Treatments
No FDA-approved treatments are currently listed for Hemicrania continua.
2 clinical trialsare actively recruiting — trials can provide access to cutting-edge therapies.
View clinical trials →Treatment Centers
8 centersBaylor College of Medicine Rare Disease Center ↗
Baylor College of Medicine
📍 Houston, TX
🏥 NORDStanford Medicine Rare Disease Center ↗
Stanford Medicine
📍 Stanford, CA
🔬 UDNNIH Clinical Center Undiagnosed Diseases Program ↗
National Institutes of Health
📍 Bethesda, MD
🔬 UDNUCLA UDN Clinical Site ↗
UCLA Health
📍 Los Angeles, CA
🔬 UDNBaylor College of Medicine UDN Clinical Site ↗
Baylor College of Medicine
📍 Houston, TX
🔬 UDNHarvard/MGH UDN Clinical Site ↗
Massachusetts General Hospital
📍 Boston, MA
🏥 NORDMayo Clinic Center for Individualized Medicine ↗
Mayo Clinic
📍 Rochester, MN
👤 Mayo Clinic Center for Individualized Medicine
🏥 NORDUCLA Rare Disease Day Program ↗
UCLA Health
📍 Los Angeles, CA
Travel Grants
No travel grants are currently matched to Hemicrania continua.
Community
No community posts yet. Be the first to share your experience with Hemicrania continua.
Start the conversation →Latest news about Hemicrania continua
Disease timeline:
New recruiting trial: Nurse Intervention Trial
A new clinical trial is recruiting patients for Hemicrania continua
Caregiver Resources
NORD Caregiver Resources
Support, advocacy, and financial assistance for caregivers of rare disease patients.
Mental Health Support
Rare disease caregiving can be isolating. Connect with counseling and peer support.
Family & Caregiver Grants
Financial assistance programs specifically for caregivers of rare disease patients.
Social Security Disability
Learn how rare disease patients may qualify for SSDI/SSI benefits.
Questions for your doctor
Bring these to your next appointment
- Q1.How confident are you that my diagnosis is hemicrania continua, and what other conditions were ruled out?,What dose of indomethacin should I start with, and how will we know if it is working?,What should I do if I cannot tolerate indomethacin — what are my other options?,How long will I need to take medication, and is there any chance the condition will go into remission?,Are there any lifestyle changes or triggers I should be aware of that could make my headaches worse?,Should I have any regular monitoring tests (such as kidney function or blood pressure) while on long-term indomethacin?,Are there any clinical trials or newer treatments I should know about?
Common questions about Hemicrania continua
What is Hemicrania continua?
Hemicrania continua is a rare but distinct type of chronic headache disorder. The name means 'continuous one-sided headache' in Latin, which describes its most defining feature: a constant, unrelenting headache that stays on one side of the head — always the same side — without switching. The pain is present every day, all day, and never fully goes away, though it can get worse in flares. During these flares, people often experience additional symptoms on the same side as the headache, such as a red or watery eye, a drooping eyelid, a stuffy or runny nose, or a feeling of restlessness and agit
How is Hemicrania continua inherited?
Hemicrania continua follows a sporadic inheritance pattern. Genetic counseling can help families understand recurrence risk and testing options.
At what age does Hemicrania continua typically begin?
Typical onset of Hemicrania continua is adult. Age of onset can vary across affected individuals.
Are there clinical trials for Hemicrania continua?
Yes — 2 recruiting clinical trials are currently listed for Hemicrania continua on UniteRare. See the clinical trials section on this page for phase, sponsor, and site details sourced from ClinicalTrials.gov.
Which specialists treat Hemicrania continua?
18 specialists and care centers treating Hemicrania continua are listed on UniteRare, sourced from ClinicalTrials.gov principal investigators, published research, and the NPPES NPI registry.