Ski sickness or Häusler's disease is a form of motion sickness suffered by some skiers when weather conditions are bad. Poor visibility in heavy fog can bring on the condition. Psychological factors such as fear of heights, fear of mountains, high speed and falling may contribute as well as the atmospheric pressure changes in the ear when descending rapidly from high to low altitude. Symptoms are similar to other sicknesses brought on by motion, namely dizziness, headaches and nausea and in more extreme cases vomiting.
In these whiteout conditions the brain is unable to accurately determine orientation or movement. The condition is caused by the rhythmic turning motion of skiing and other effects such as a reduction in sensory feedback from constrained feet. Rudolf Häusler of the University of Berne, who first described this disease in 1995, thinks that ski sickness could affect up to 10% of skiers. Professor Häusler found that over-the-counter prescription medicines for motion sickness relieved the symptoms for most sufferers.