The nerves conduct at almost normal speed but still do not work properly. In most types of HMSN, there is a limited disability, very slow progression of the disease and normal life expectancy. However, the severity of symptoms and rate of progression of the disorder can vary widely from person to person. The first symptom of HMSN is often difficulty in walking. Typically, the knees have to be raised higher than normal to lift the feet off the ground.
Some individuals have difficulty in maintaining balance while standing.
Typical symptoms occurring in the upper limbs include difficulty picking up articles or dropping things due to weakness in the fingers, hands and wrists. Many people with HMSN experience fatigue. This may further affect an individual's balance or ability to bend over. Hammer toes or clawed toes may develop. Weakness, accompanied by tremors may be experienced in the hands and forearms, usually in later stages.