Human: Is it normal to have an uncontrollable fear of heights? Assistant: 
Yes, it is normal to have an uncontrollable fear of heights. Height phobia is a type of specific phobia and is characterized by feelings of dread or anxiety when exposed to heights. Common symptoms include sweating, trembling, feeling dizzy or faint, nausea, and difficulty breathing. It is estimated that about 5% of the population has some form of height phobia.