Headache in High Altitude

Headache is the most common symptoms travelers experience during travel to high altitude. It is found to be experienced by more than half of the travelers above 2,500 meters. And, probably almost all the travelers going to high altitude experience headache at least once in their lifetime.

At high altitude, headache is an abnormal response of body to the hypoxia and is manifested as an isolated symptoms called as “High altitude Headache” or a mandatory component of “Acute Mountain Sickness”. And, other headaches that are not-altitude-related (but occurring in altitude) are sinus headache, tension type headache, migraine, dehydration, environmental effect (d/t cold, light reflection), stroke and sometimes fatal “cerebral venous thrombosis” headache or subarachnoid bleed headache.

As headache is a very common symptom experienced anywhere, it usually is not taken too seriously and often ignored. Headache of non-serious origin in high altitude like headache due to dehydration, environmental effect & high altitude headache are benign and are easily treated with general measures. But, headache should never be ignored and other red-flag signs/warning signs should always be checked for.

Red Flag signs:

  • Sudden onset severe headache (Not experienced before)
  • Associated with fever, vomiting, seizure, weakness (paralysis), blurred vision
  • Personality change
  • Disturbed consciousness/confusion
  • Drowsiness

Distinguishing different types of headache:

  • High altitude headache:
    • Develops within 24 hours of ascent to high altitude (>2,500 meters) and subsides within 8 hours of descent
    • Isolated, mild to moderate intensity headache without other symptoms like nausea, poor appetite, fatigue, dizziness is classified at high altitude headache.
    • Caused by mild brain edema as a result of hypobaric hypoxia

  • Headache of Acute mountain sickness:
    • Headache associated with any of the following symptoms:
      • Poor appetite or nausea or vomiting, Dizziness, Fatigue and Poor sleep
      • Develops after 8 of ascent to high altitude (>2,500 meters)
    • Caused by the brain edema as a result of failure to acclimatize in hypobaric hypoxia.

  • Migraine headache:
    • Similar to character as in sea level but headache may not be typical “one-sided headache“. Often hard to distinguish from the headache of AMS but following characteristics are important to distinguish it from other headache:
      • Often unilateral but not necessarily. Moderate-Severe intensity pulsating headache lasting few to many hours and associated with “Photophobia
    • Migraine attacks are found to be aggravated by hypoxia at high altitude.

  • Sinus headache:
    • Often confused with migraine headache at altitude.
    • Typical features include
      • Pain, pressure and fullness in cheeks, brow or forehead
      • Worsening pain on bending forward or lying down
      • Stuffy nose
      • Achy feeling in upper teeth

  • Tension type headache:
    • Mild to moderate headache described as “feeling like a tight band around head“.
    • Typical features include:
      • Dull aching headache
      • Sensation of tightness or pressure across the forehead or on the sides and back of head
      • Tenderness in scalp, shoulder and neck muscles

  • Cerebral venous thrombosis:
    • This is clot of blood in the veins around the brain. Potentially fatal and often presenting with continuous headache with stroke like features.
    • Typical features include:
      • Unusual headache (not previously experienced) and associated with blurred vision, feeling/being sick, neurological loss, drowsiness or seizures.
      • Headache worsening on bending forward or lying down.

  • Subarachnoid bleed headache:
    • This is bleeding in the subarachnoid space (covering of brain).
    • Typical features include:
      • Very severe thunderclap headache (Worst headache of lifetime)
      • Often associated with neck stiffness and
      • Feeling/being sick

What should I do to treat headache?

You can always try some “over-the-counter” drugs like Paracetamol, Aspirin, Ibuprofen and take few more measures like keeping yourself warm and hydrating. But, if the headache is persistent and is accompanied by other red-flag signs then it’s the time to seek further medical help.

Always look for the red-flag signs of headache and watch out for symptoms of altitude illnesses. If headache is unusual and with red-flag signs then don’t hesitate to climb down and get consultation.

Safe Travels!

Dr. Santosh Baniya, MD (November 2022)