The early symptoms of amyotrophic lateral sclerosis include slight muscle weakness, clumsy hand movements, and/or difficulty performing tasks that require delicate movements of the fingers and/or hands. Muscle weakness in the legs may cause tripping and falling. Affected Individuals may develop problems with moving, swallowing (dysphagia), speaking or forming words (dysarthria), and breathing (dyspnoea).



Other symptoms of this disorder include progressive weakness of the lips and impairment and/or loss of function of the tongue, mouth, and/or voice box (bulbar symptoms). Leg cramps may occur during the night, most frequently in the calf and/or thigh muscles. Gradually, additional muscles become involved. Amyotrophic lateral sclerosis may progress quickly or slowly.

Leg Cramps

Other symptoms may include the uncontrolled twitching of muscles (fasciculation), stiffness in the legs, and/or coughing. People with this disorder will have exaggerated deep muscle reflexes. Marked weight loss occurs in approximately 5 percent of cases.


As the ability to move becomes progressively impaired, people with this disease are at increased risk for respiratory failure. People with amyotrophic lateral sclerosis are also at increased risk for acute inflammation of the lungs, caused by the inhalation of food or stomach contents (aspiration pneumonia). An overall decrease in the ability to move, including the ability to swallow, may also result in inadequate nutrition.

Because people with ALS usually retain their ability to perform higher mental processes such as reasoning, remembering, understanding, and problem solving, they are aware of their progressive loss of function and may become anxious and depressed. A small percentage of individuals may experience problems with language or decision-making, and there is growing evidence that some may even develop a form of dementia over time.


As the disease progresses, typically over the course of three to five years, the individual will gradually lose the ability to stand or walk. In time, many patients will require mechanical assistance to breath. A small percentage of people with ALS experience a gradual stabilization of symptoms and may maintain that level (plateau) for a few years.