Amyotrophic lateral sclerosis (ALS) is a progressive disease, which leads to the degeneration of motor neurons or the nerve cells that control muscle movement. ALS may be inherited or appear sporadically. Diagnosing ALS is difficult, and diagnosis usually is reached by eliminating other neurological disorders once symptoms have begun to appear.

Early-stage symptoms

The initial symptoms of ALS generally begin between ages 55 and 75, but can occur at any age. The first symptoms can be very subtle. They may include muscle weakness, muscle twitches, muscle cramps, stiff muscles (spasticity), shortness of breath, and unintended weight loss. For some people, initial signs of the disease may include speech or swallowing problems.

Late-stage symptoms

As the disease progresses and more nerve cells are destroyed, muscle weakness increases, eventually affecting chewing, swallowing, speaking, and breathing. As the respiratory system weakens, patients eventually lose the ability to breathe on their own and may need to use a ventilator.

In addition to muscle cramps that may cause discomfort, some ALS patients may develop painful neuropathy or nerve disease or damage.

Usually, ALS does not affect bowel or bladder control, the senses, or thinking ability, so patients can remain actively involved with their family and friends. However, some individuals may experience problems with language or decision-making, and there is growing evidence suggesting that some patients may develop a form of dementia as the disease progresses.

Pseudobulbar affect

Pseudobulbar affect (PBA) is a rare symptom that can occur in some patients with ALS. PBA is characterized by sudden, uncontrollable bouts of laughter or tears. These outbursts are often inappropriate with the situation and may not match how the patient is actually feeling. The outbursts can be quite severe and may occur as often as several times a day. 


ALS News Today is strictly a news and information website about the disease. It does not provide medical advice, diagnosis or treatment. This content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. Never disregard professional medical advice or delay in seeking it because of something you have read on this website.