Amyotrophic lateral sclerosis (a-my-o-TROE-fik LAT-ur-ul skluh-ROE-sis), or ALS, is a progressive nervous system (neurological) disease that destroys nerve cells and causes disability.
ALS is often called Lou Gehrig's disease, after the famous baseball player who was diagnosed with it. ALS is a type of motor neuron disease in which nerve cells gradually break down and die.
Doctors usually don't know why ALS occurs. Some cases are inherited.
ALS often begins with muscle twitching and weakness in a limb, or slurred speech. Eventually, ALS affects control of the muscles needed to move, speak, eat and breathe. There is no cure for ALS, and eventually the disease is fatal.
Early signs and symptoms of ALS include:
ALS often starts in the hands, feet or limbs, and then spreads to other parts of your body. As the disease advances and nerve cells are destroyed, your muscles progressively weaken. This eventually affects chewing, swallowing, speaking and breathing.
ALS doesn't usually affect your bowel or bladder control, your senses or your thinking ability. It's possible to remain actively involved with your family and friends.
ALS is inherited in 5 to 10 percent of cases, while the rest have no known cause.
Researchers are studying several possible causes of ALS, including:
Established risk factors for ALS include:
Environmental factors may trigger ALS. Some that may affect ALS risk include:
As the disease progresses, people with ALS experience complications, which may include:
Over time, ALS paralyzes the muscles you use to breathe. You may need a device to help you breathe at night, similar to what someone with sleep apnea might wear. For example, you may be given continuous positive airway pressure (CPAP) or bi-level positive airway pressure (BiPAP) to assist with your breathing at night.
Some people with advanced ALS choose to have a tracheostomy — a surgically created hole at the front of the neck leading to the windpipe (trachea) — for full-time use of a respirator that inflates and deflates their lungs.
The most common cause of death for people with ALS is respiratory failure. On average, death occurs within three to five years after symptoms begin.
Most people with ALS will develop trouble speaking over time. This usually starts as occasional, mild slurring of words, but progresses to become more severe. Speech eventually becomes more difficult for others to understand, and people with ALS often rely on other communication technologies to communicate.
People with ALS can develop malnutrition and dehydration from damage to the muscles that control swallowing. They are also at higher risk of getting food, liquids or saliva into the lungs, which can cause pneumonia. A feeding tube can reduce these risks and ensure proper hydration and nutrition.
Some people with ALS experience problems with memory and making decisions, and some are eventually diagnosed with a form of dementia called frontotemporal dementia.