What Are the Symptoms of ALS?

Medically Reviewed by Poonam Sachdev on June 05, 2023
8 min read

ALS (amyotrophic lateral sclerosis), also known as Lou Gehrig's disease, can show up differently in people based on things like sex, age, and race. Your sex can also play a role in what type of ALS you get and how quickly it gets worse. 

ALS symptoms in women can differ from those in men, depending on what caused your disease. Knowing about these differences may help you spot your symptoms and start treatment sooner so you can possibly slow down progression of the disease. And it could help researchers better target treatments.

ALS can be sporadic (we don't know the cause) or familial (caused by your genes). About 90% to 95% of people with ALS have the sporadic type. Early symptoms of sporadic ALS can be different in women and men. Being in the military, being exposed to toxins, and smoking may increase your risk for ALS.

Symptoms can start as a weak feeling in your hands or feet. The disease attacks the brain cells that control a lot of your muscle movement. Eventually, it weakens your diaphragm, a muscle needed for your lungs to work. Most people with ALS die from respiratory failure. ALS still has no cure.

Signs of ALS can appear gradually.

You may notice a funny feeling in your hand that makes it harder to grip the steering wheel. Or you may start to slur your words before any other symptoms show up. Each person with the disease has different symptoms, especially at first.

Some common early symptoms include:

  • Stumbling
  • A hard time holding items with your hands
  • Slurred speech
  • Swallowing problems
  • Muscle cramps
  • Worsening posture
  • A hard time holding your head up
  • Muscle stiffness

ALS may affect only one hand at first. Or you may have problems in just one leg, making it hard to walk in a straight line. ALS affects upper and lower motor neurons, which are nerves in your brain that control your muscles. Your symptoms can differ based on which types of neurons your disease affects first. ALS weakens and destroys your neurons so they stop communicating with your muscles.

Over time, the disease affects almost all of the muscles you control. But it doesn’t harm all muscles and organs in the body. The heart and bladder, for instance, usually stay healthy.

ALS usually occurs in one of two main ways: limb (spinal) onset or bulbar onset. 

Symptoms start in your arms or legs. Also called spinal ALS, limb onset tends to worsen more slowly than bulbar onset. 

In your arms, it may cause:

  • Weakness in your hands
  • Stiffness or cramping in your arms or hands
  • Reduced use of your fingers (fumbling or dropping items, having a hard time turning keys)

In your legs, it may cause:

  • Tripping 
  • Stumbling
  • Awkwardness when you walk or run
  • Foot drop (when your foot stomps on the ground instead of rolling as you stride)

Some limb onset symptoms can show whether the disease is affecting your lower or upper motor neurons first.

If your lower motor neurons are being affected first, you may have:

  • Involuntary muscle twitching (called fasciculations)
  • Weakness and cramps in muscles
  • Decreased muscle tone and/or atrophy (thinning muscle mass)
  • Weakened reflexes
  • Feeling short of breath when you're resting

If your upper motor neurons are being damaged first, you may have:

  • Stiff or rigid muscles
  • Increased or hyperactive reflexes
  • Less control over laughing or crying

It’s less common for ALS to begin this way. It affects your brainstem, which is the lower area of your brain that connects to your spinal cord. Specifically, it impacts the corticobulbar area that controls muscles in your neck, face, and head. Bulbar onset usually worsens more quickly than limb onset.

Symptoms can include:

  • Slurred speech
  • Swallowing problems
  • Changes in your voice
  • Muscle spasms in your face or throat
  • Jerking in your jaw
  • Twitching in your tongue that you can't control 

No matter where your symptoms start, they’ll move on to other parts of your body. Most people with ALS have bulbar onset symptoms at later stages of the disease.

As ALS gets worse, more of your muscles and activities are affected. You may have:

  • Weaker muscles
  • Less muscle mass
  • More serious chewing and swallowing problems
  • A hard time being understood when you speak
  • Trouble breathing

ALS symptoms in women can be different than in men. With sporadic ALS, men are more likely to have limb onset and women are more likely to have bulbar onset. But there's not much difference in survival rates between men and women with ALS.

ALS is more likely to occur in men, but as people get older, it happens equally in men and women. 

Researchers aren't sure why there are differences based on sex. They think it could have to do with how our bodies respond to toxins. Research looking at sex hormones suggests that women may have some protection from developing ALS. 

During the early stages of the disease, some forms of treatment might help give you a better quality of life. They include:

Physical therapy: It focuses mostly on larger muscles used for standing, walking, balancing, reaching, and so on.

Occupational therapy: It helps with smaller muscle activities, such as buttoning a shirt, using a fork or spoon, or brushing your teeth.

Speech therapy: It can help you speak a little more clearly when you lose control of the muscles of the tongue. Speech therapists can help you manage swallowing problems, too.

In addition to these therapies, certain tools and new technologies can also assist those with ALS. Some of them include:

  • Motorized wheelchairs
  • Continuous positive airway pressure (CPAP) to help with breathing during sleep
  • Speech-generating devices to help those with slurred speech
  • Computers with eye-recognition software that help a person communicate when speech and hand control are lost

At more advanced stages, you may need a machine to keep your lungs working. If chewing and swallowing become too hard, even with small bites or a liquid diet, you may need a feeding tube.

A muscle cramp in your leg or a weak feeling in your hand once in a while isn’t usually enough to send you to the doctor. But if those feelings last for days or weeks, you should make an appointment.

Pay attention to changes in how the muscles in your arms and legs feel. Listen to friends or family if they point out a change in your speech or how you walk.

You can start by seeing your regular doctor. If you think that the weakness or tingling is nerve-related, see a neurologist. This is a doctor who specializes in diseases affecting the brain and nervous system.

Some early ALS symptoms are the same as those of less serious conditions.

Many of these, such as carpal tunnel syndrome (a problem with the nerves in your wrist), can be treated successfully. To know for sure, don’t hesitate to describe your symptoms to a doctor. The earlier you know what’s causing your symptoms, the sooner you can start to treat them.

Physical Exam

Your first step is a full exam by a neurologist. This is a doctor who specializes in disorders of the nervous system, including your brain and spinal cord.

This exam will include lots of questions about your symptoms, health history, and family. Bring notes with you so it will be easier to answer their questions.

In a physical exam, your neurologist will also look for the signs of ALS, including:

  • Muscle weakness, often on only one side of the body
  • Slurred or slowed speech and other signs of muscle weakness in your mouth and tongue
  • Muscle twitches
  • Muscles that have shrunk in size, have unusual reflexes, or are tight and rigid
  • Emotional changes such has out-of-control laughing and crying or a loss of good judgment or social skills

Blood and Urine Tests

These won’t detect ALS, but common lab tests can be used to rule out other diseases that have the same kinds of symptoms. Your blood samples and urine may be used to test for:

  • Thyroid disease
  • Lack of vitamin B12
  • HIV
  • Hepatitis (inflammation of the liver)
  • Autoimmune diseases (in which your body’s immune system attacks its own healthy cells)
  • Cancer

In some cases, a doctor may also use a what’s called a lumbar puncture, or spinal tap, to take fluid from your spine to look for problems.

In rare cases where ALS runs in a family, genetic tests may be run to figure out whether a gene mutation is linked to your disease.


Scans such as magnetic resonance imaging, or MRI, can’t directly diagnose ALS. That’s because people with the condition have normal MRI scans. But they are often used to rule out other diseases.

For instance, a spinal cord tumor or herniated disk in the neck can cause some symptoms that mimic ALS but will show up on a scan of the spine and neck, ruling out ALS as the cause of the symptoms.

Muscle and Nerve Tests

If basic lab tests don’t point toward a different health issue, your neurologist can use more advanced tests. They’re called “electrophysiological tests,” and doctors can use them to confirm that the way your muscles and nerves are acting fits the definition of ALS.

These tests can show abnormal results if you have ALS, but your doctor could also decide from the results that you have damage to your nerves or a muscle disease that’s not ALS.

These tests include:

Electromyography: EMG is one of the most important tests used to diagnose ALS. Small electric shocks are sent through your nerves. Your doctor measures how fast they conduct electricity and whether they’re damaged. A second part of the test also checks the electrical activity of your muscles. In both cases, your doctor will be able to see clear abnormal patterns of activity if you have ALS.

A nerve conduction study: This measures how well your nerves send signals. Only about 10% of ALS patients have abnormal nerve conduction study results, but the test can also suggest other diagnoses.

A muscle biopsy: A small sample of your muscle tissue may be taken if your doctor thinks you have a muscle disease other than ALS. You will be given something to numb the area before the tissue is taken.

Second Opinions

There’s no one test that can give you and your doctor a certain diagnosis of ALS. So many of its symptoms can be caused by multiple conditions.

Because of this, many patients like to look for a second opinion after getting an ALS diagnosis. A second neurologist may do a different round of tests that shows something new.

Proof of Progression

Part of the definition of ALS is that it’s a progressive disease – that is, it gets worse over time.

So once you have your first diagnosis of ALS, your doctor will likely recommend repeating all the tests in 6 or more months to see whether your disease has changed at all.

If the tests show a worsening of the symptoms and muscle and nerve function, your diagnosis will likely be confirmed.