What Is ALS? Symptoms, Diagnosis, and Treatment Explained
ALS (amyotrophic lateral sclerosis) is a progressive motor neuron disease that damages the nerve cells controlling voluntary muscles, leading to weakness, loss of movement, and eventually difficulty breathing. It is also known as Lou Gehrig's disease, after the baseball player diagnosed with it in 1939, and is classified as a form of motor neuron disease (MND). The ALS Therapy Development Institute (ALS TDI) describes itself as the largest drug discovery lab in the world focused solely on finding treatments for ALS — a useful starting point if you want to understand both the disease and where research currently stands.
What ALS Is and Who It Affects
ALS attacks motor neurons — the nerve cells in the brain and spinal cord that carry signals to muscles. As these neurons degenerate, muscles stop receiving signals and begin to weaken and waste away. The disease does not typically affect the senses (sight, hearing, touch, taste, smell) or, in most cases, bladder and bowel control, which distinguishes it from some other neurological conditions.
The terminology can be confusing, so it helps to separate the names:
| Term | What it refers to |
|---|---|
| ALS (amyotrophic lateral sclerosis) | The most common form of motor neuron disease, especially in the U.S. |
| Lou Gehrig's disease | A common name for ALS in the U.S., after the famous player |
| Motor neuron disease (MND) | An umbrella term for conditions that affect motor neurons; ALS is the most common |
| Charcot's disease | An older name for ALS, after the neurologist Jean-Martin Charcot |
ALS can affect adults of any age, though it most commonly appears in middle to later life. Because the disease varies in how it starts and progresses, no two people experience exactly the same path.
Early Signs and Symptoms
Symptoms usually begin subtly and may be noticed first in the hands, arms, legs, or muscles involved in speaking and swallowing. Common early signs include:
- Muscle weakness — trouble gripping objects, lifting, walking, or climbing stairs
- Muscle twitching (fasciculations) and cramping
- Muscle wasting (atrophy) in the hands, arms, or legs
- Slurred or thick speech (dysarthria)
- Difficulty swallowing (dysphagia)
- Tripping or dropping things due to weakness
- Emotional changes in some people, such as inappropriate laughing or crying (pseudobulbar affect)
Because these symptoms overlap with many other, more treatable conditions, they do not by themselves mean a person has ALS. That overlap is one reason diagnosis is not immediate.
How ALS Is Diagnosed
There is no single test that confirms ALS. Diagnosis is a clinical process: a neurologist evaluates symptoms, examines motor and sensory function, and rules out conditions that mimic ALS — such as certain nerve disorders, spinal cord problems, and other motor neuron diseases.
The process typically involves:
- Medical history and neurological exam — assessing weakness, reflexes, muscle tone, and coordination
- Electromyography (EMG) — measuring electrical activity in muscles to detect motor neuron damage
- Nerve conduction studies — checking how well nerves carry signals
- MRI and other imaging — looking for structural causes of symptoms
- Blood and other lab tests — excluding treatable conditions with similar symptoms
Because ALS is diagnosed by exclusion, confirming it can take time. Symptoms may need to be observed and monitored before a neurologist is confident in the diagnosis. This delay is common and does not necessarily indicate uncertainty about the eventual conclusion.
Current Treatment Approaches
There is currently no cure for ALS, and treatment focuses on slowing progression where possible, managing symptoms, and maintaining quality of life. What treatment can and cannot do is important to understand:
- Can slow the rate of decline in some people, depending on the specific therapy and the individual
- Can relieve symptoms such as muscle cramps, spasticity, excess saliva, and breathing difficulty
- Can support nutrition, communication, and mobility through assistive devices and therapies
- Cannot reverse existing motor neuron damage or restore lost muscle function
- Cannot stop progression entirely in most cases
Care is typically delivered by a multidisciplinary team — neurologists, physical and occupational therapists, speech-language pathologists, respiratory specialists, dietitians, and social workers — because ALS affects many body systems over time. A neurologist is the right person to discuss which specific treatments are appropriate for an individual, as options and eligibility vary.
Where to Find Credible Research Updates and Support
Because ALS research moves quickly, reliable updates matter. The ALS Therapy Development Institute (als.net) is one source focused specifically on ALS drug discovery, and it offers a way to receive updates through its subscribe page. Other credible resources include academic medical centers with ALS clinics, national ALS associations, and patient registries that connect people to research studies.
When evaluating any ALS information, look for:
- Named medical or research institutions behind the content
- Clear distinction between approved treatments and experimental research
- Dates on research updates, since findings evolve
- Contact routes to ALS clinics or specialists for personal medical questions
For anyone newly researching ALS — whether for themselves or a family member — the practical next step is usually to consult a neurologist experienced with motor neuron disease, while using research organizations like ALS TDI to stay informed about the science as it develops.