Amyotrophic lateral sclerosis (ALS) is a rapidly progressing neurodegenerative disease that attacks the nerve cells in the brain and spinal cord that control voluntary muscle movement. As these nerve cells, called motor neurons, decline, they stop sending messages to the muscles. This causes the muscles to weaken, twitch, and atrophy (lose muscle mass and deteriorate). ALS was once referred to as “Lou Gehrig’s disease” after the New York Yankees baseball player who retired in 1939 because of the disease.
Age range most commonly affected by ALS
Percentage of cases that are sporadic (not hereditary)
Average survival in years
ALS most commonly affects people between the ages of 40 and 70, though younger and older people can also develop the disease. According to the National Institutes of Health, men are slightly more likely to develop the disease than women, though as age increases, this difference is reduced. Some studies suggest that military veterans also have an increased risk of the disease. The reason for this is unknown but may be due to exposure to lead, pesticides, and other environmental toxins during their service. Ongoing research in this area is looking into the impact of environmental, behavioral, and occupational factors on the development and progression of this disease.
While the disease is caused by a decline in motor neuron function, scientists don’t yet know why it occurs in some people and not others. In 5 to 10 percent of cases, the disease is inherited from a parent with the disease-causing gene. Researchers have identified more than a dozen genetic mutations that cause the hereditary form of ALS. However, for 90 to 95 percent of cases, the disease is sporadic, meaning it happens without any clear cause, risk factor, or family history of the disease. The family members of individuals with sporadic ALS do not have an increased risk of developing the disease.
The main symptoms of ALS include muscle weakness, stiffness, and atrophy. Early signs, such as muscle twitches, cramps, stiffness, or weakness in one body part, can be subtle. Symptoms usually first appear in a hand or arm. This might look like difficulty with tasks including buttoning a shirt, turning a lock, or writing. In some cases, the disease begins by affecting one leg, causing trouble with walking or more frequent stumbling.
As the disease progresses, people with ALS have difficulty standing, moving, walking, swallowing, and speaking. Eventually, they lose their ability to breathe without the support of a ventilator.
The disease is not known to be associated with cognitive impairment, but recent studies suggest some people with ALS may develop a form of dementia that affects memory and decision-making.
ALS is ultimately fatal, typically due to respiratory failure when the muscles needed to breathe become too weak. On average, people with ALS survive about three to five years while about 10 percent will live 10 years or more.
There is not a specific test to diagnose ALS. Doctors typically diagnose the disease by reviewing a person’s medical history and performing physical and neurologic exams. They may also use electromyography (EMG) to test nerve and muscle function and conduct other tests, such as blood and urine tests, a spinal tap, and magnetic resonance imaging (MRI), to rule out other conditions.
There is no cure for ALS or treatment to reverse its damage. However, medications can help slow the disease’s progression and manage symptoms such as muscle cramps, spasticity, pain, and excess saliva. Two FDA-approved medications for ALS have been shown to prolong survival. People with ALS may also experience sleep disturbances and depression, which can be treated with medication and therapy.
As the disease progresses, physical and occupational therapy, speech therapy, communication devices, and special equipment can help people with ALS remain mobile and independent for as long as possible. Later on, when symptoms worsen, people with ALS may require help from a caregiver as well as a feeding tube or a ventilator.
Current research efforts are working to identify potential risk factors, understand the disease’s progression, and develop better ways to diagnose, assess, and treat ALS.
Additional research projects are investigating the disease mechanism of ALS to identify new targets for treatment, the mutations that occur in motor neurons and cause this disease, and whether metabolic changes and nutrition impact disease progression.
Explore more brain disease information, research, and stories.
Discover the latest news in brain disease research, hear stories from people affected by brain disease and their caregivers, read up on brain disease-specific information, and more.
Orlena was driving with her young daughter in the car when she suffered a stroke because of a rare brain vessel disorder called Moyamoya. After two brain surgeries and six months unable to care for her daughter, Orlena began to reclaim her independence and became a Moyamoya advocate.
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At 15 years old, Zoe has been navigating her Tourette syndrome diagnosis for eight years. “I had to figure out at a young age how my emotions affect my tics, from good to awful ways. It has been frustrating to figure out on my own and learn to deal with. This was the first moment in my life where my parents couldn’t fix something for me.”
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Sasha was diagnosed with epilepsy after sustaining a soccer-related brain injury in high school. Since then, Sasha has worked to find both a treatment that controlled her seizures and a career that fulfilled her desire to care for others. “Life isn’t meant to be lived taking multiple medications and having seizures you can’t control.”
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Before frontotemporal lobe dementia, sometimes called Pick’s disease, Ken Keene Sr. was a respected community member and a handyman who could fix anything. For his oldest son and namesake Ken Keene Jr., there was nothing his father couldn’t do: “To my family, he was just that super dad. Then all of a sudden he’s reaching out for help.”
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It started with a twinge. After a simple surgery and some physical therapy, Morgan wasn’t getting better. It took two more surgeries before she was diagnosed with Complex Regional Pain Syndrome (CRPS) type II.
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In 2018, Kelly was diagnosed with glioblastoma after an MRI confirmed that a golf-ball-sized tumor above her right ear was affecting the left side of her body. After surgery to remove the tumor, Kelly was able to get through her darkest days with a healthy dose of humor. Now she is an advocate for other patients living with strokes and brain tumors.
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When her father was diagnosed with vascular dementia in 2005, Nancy quickly shifted into the role of his caregiver. Nancy and her sisters drew from their individual strengths to provide their father with medical assistance and emotional support until his passing in 2012. At that time, he was diagnosed again with Lewy body dementia. “No matter what your financial situation, there’s probably going to be help out there… Just don’t do it alone, because burning yourself out is not going to help anybody.”
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Maureen worked as a high school English teacher until she started experiencing a confusing array of symptoms that affected her ability to work, along with her relationships with family and friends. After visiting numerous specialists for years, Maureen received a delayed diagnosis of Lewy body dementia. Now Maureen wants to raise awareness about what life is like with living with this disease. “I felt that I just wanted to offer something to this community that I hadn’t been able to find really.”
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For the first 32 years of his life, Joey experienced seizures from epilepsy. For several years, Joey worked hard in his career as a pipe welder and in construction until his seizures started happening more frequently and intensely. Brain surgery became Joey’s only viable option for treatment. Doctors were unsure if Joey would be able to survive after finding more brain damage than expected, but he surprised everyone by thriving during his post-surgery recovery.
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At age 40, Ben was perfectly healthy and active until he started noticing the early symptoms of a neurological condition that weakened his physical movements. After a 2-year search for his diagnosis of X-linked adrenoleukodystrophy, he began his journey as an advocate for others living with rare diseases. Last year, Ben joined the board of the American Brain Foundation to further his impact.
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In 2002, while her young daughter battled a fatal diagnosis of pons glioma, Michele experienced a life-threatening brain hemorrhage when a brain malformation she likely had since birth ruptured. She experienced drastic changes in the way her brain functioned, especially in regard to memory and spatial awareness. Today, Michele is still learning to adjust. “When someone’s brain is not functioning correctly it impacts everything in their life. It impacts how they think, how they feel about themselves, it’s a very hopeless space to be in as a person.”
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Matt is a husband, father, and professional photographer. Over the past 11 years, he has had surgeries and radiation to remove five benign brain tumors. Following the third surgery, he began to experience more struggles in his daily life. “I think the biggest loss is my relationship to my family. They saw me as the dad and strong. Now they can’t count on me as much. It’s important to support people with brain disease ‘cause it can happen to anybody.’”
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When she was in her early 30’s, Mary Jo’s relationship with her parents was forever altered by brain disease. Her father suffered a subdural hematoma, was diagnosed with diabetic neuropathy, and experienced a stroke while her mother was diagnosed with Alzheimer’s and dementia. “They’re a responsibility that I have to take care of as they have taken care of me.”
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Tom suffers from dystonia, a painful neurological movement disorder with no known cure. When he first started experiencing strange pains and cramps in his neck muscles, he saw chiropractors and physical therapists—but when this didn’t help, Tom started down a long and painful road to an eventual diagnosis. Before his diagnosis at 30 years old, Tom was an athlete and an entrepreneur, but as his symptoms worsened, even performing everyday tasks became a challenge. Before long, the pain became debilitating. Over time, Tom learned to accept his new limitations and focus on his physical and mental health.
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