Dry mouth is a great big side effect for most antihistamines. You tend to feel like you got that dry, cotton-mouth going on. And then with the decongestants-- raising the blood pressure ...
Medically reviewed by Femi Aremu, PharmD Altitude sickness refers to symptoms of low oxygen, which may happen at elevations at least 8,000 feet above sea level. Symptoms may range from mild to severe.