Walking becomes increasingly difficult, and the person may stumble or fall. Speech may become slurred. The patient may begin having trouble swallowing or eating. Gradually, he or she may lose the ability to recognize others, although many HD patients retain an awareness of their surroundings and can express emotions. Generally, the illness runs its full terminal course in 10 to 30 years.
Death often results from pneumonia when the end-stage patient is bedridden.
Other patients die from infections or other physical complications including injuries sustained in falls and other accidents. It has been observed that the earlier in life the symptoms of HD appear, the faster the disease progresses. In most cases it begins in middle age, but some people develop symptoms of HD before the age of 20. The person may develop seemingly minor movement disorders, such as slowness, rigidity, tremor or a rapid muscular twitching. People with juvenile HD also may have seizures and mental disabilities, however, which are uncharacteristic of Parkinson's disease.