Contact & Info Center

(970) 945-2601

(Verizon mobile)

  • PO Box 3084
  • Aspen, Colorado 81612

Newsletter Subscription

This is a difficult sign to evaluate. Proper fluid intake should be followed by regular, clear and copious urine output at high altitudes. Retention of fluids at high altitudes could be a sign of not acclimatizing properly, and should alert a person to be wary of AMS and other symptoms.

This by no means to be taken as a full and comprehensive explanation of acute mountain sickness, but rather a brief discussion on the most common symptoms, and what a person needs to be aware of before and after arrival at high altitudes.

The following reference books will provide a more thorough and complete discussion of acute mountain sickness:

Mountain Sickness: Prevention, Recognition and Treatment. Peter H. Hackett, MD.
Medicine for Mountaineering. James A. Wilkerson, MD.
Going Higher: The Story of Man and Altitude. Charles Houston, MD.
High Altitude Physiology Study. Charles Houston, MD.
The Pocket Doctor: Your Ticket to Good Health While Travelling. Stephen Bezruchka, MD.
The Medical Guide for Third World Travellers: A Comprehensive Self-Care Handbook. Robin and Dessery.


The following is a discussion on the use of Diamox (acetazolamide) for the prevention and treatment of symptoms of acute mountain sickness (AMS) at high altitudes. This discussion is by no means intended to be comprehensive, since new studies and research regarding the use of this drug are continually being conducted.

There are no medications which are recommended routinely for prevention of acute mountain sickness. Indeed, it is strongly felt that medication for this purpose may be harmful, both because of side effects and giving one a false sense of security.

Diamox is one of a few drugs that have been subjected to controlled studies. It is now generally agreed that Diamox does reduce the incidence and severity of acute mountain sickness, even in mild cases. This has been determined statistically on large numbers of people. For a given individual, however, the medication in no way should be thought of as a guarantee of freedom from mountain sickness. Serious mountain sickness has been reported, although rarely, in persons taking Diamox.

Until recently, it was thought that for effective prevention Diamox must be taken one or two days prior to ascent. We now know that it works quite quickly, and does not have to be started until the day of the ascent, or even after reaching high altitude. Diamox can be taken for the first few days at altitude and then discontinued, or continued until the highest altitude is reached. If symptoms of acute mountain sickness occur when the medication is stopped, it should be immediately started again. Recommended dosage is 250mg. (one tablet) twice a day. Side effects most noted are numbness and tingling in fingers, toes or face, which is thought to be related to direct action on peripheral nerves, and an increase in urine output. Some people have reported a sluggishness or mild depression while using Diamox.

Diamox's exact mechanism of benefit is unknown. It is a mild diuretic. It does make the blood a bit more acidic, thus allowing one to hyperventilate more, raising the blood oxygen content, without experiencing the symptoms of hyperventilation. It also decreases the cerebrospinal fluid pressure by slowing its formation, and has recently been shown to be a respiratory stimulant during sleep at high altitudes.

As one can see, Diamox is a powerful drug, and not to be regarded lightly. Therefore, it is not recommended routinely. It is recommended, however, for those persons who routinely experience acute mountain sickness, even with gradual ascent and following the recommended preventive measures. Such a person is more susceptible to acute mountain sickness than others because of individual physiological characteristics. For these people, Diamox may be an alternative to giving up the high mountains in favor of the beaches.

Please consult your physician before beginning a program of Diamox. Your physician should be able to write you a prescription.