Comparing ALS with MS

ALS Vs MS: How Do These Conditions Differ?

Neurodegenerative diseases have a profound effect on individuals and their loved ones. While our understanding of many of these conditions has improved over the years, we are still a long way off from discovering causes and cures for many of them.

Effects on the nervous system can lead to symptoms such as muscle atrophy and weakness, paralysis, fatigue, and mental impairment.

Many diseases such as Amyotrophic Lateral Sclerosis (ALS) and Multiple Sclerosis (MS) share some common traits. They also have many significant differences, however, including their impact on the human body, who they are likely to affect and what the prognosis is.

Here we take a closer look at the differences and similarities between ALS and MS and what it means for individuals with these conditions.

Similarities Between ALS and MS

The reason that some have difficulty distinguishing ALS vs MS is because they share several symptoms.

Shared symptoms may include:

  • Tiredness
  • Involuntary muscle spasms
  • Muscle weakness
  • Slurred speech
  • Difficulty in swallowing
Individual with muscle weakness
Muscle weakness is a symptom of both ALS and MS

It’s true that both diseases attack the body and affect the brain and nervous system. Both are quite difficult to definitively diagnose in their early stages and they both have an impact on quality of life for the individuals affected by them. Furthermore, there has not been a cure discovered for either of these conditions.

Despite their common traits, the differences between these two diseases are greater than their similarities.

Differences Between ALS and MS

The first big difference is the mechanism that ALS and MS work through.

When our bodies are perfectly healthy, nerves send impulses from the brain to our muscles telling them to help us bend, stretch, walk and so on.

Autonomic responses from nerve impulses control blood pressure, breathing and heart rate. With ALS, the neurons that deliver impulses are gradually damaged and destroyed so that important messages can’t get through.

Complete destruction of these neurons has fatal consequences, with later stage symptoms involving paralysis, breathing problems and eventual death.

MS acts in a different way by damaging the coating that protects nerve cells. While this doesn’t destroy the neurons themselves, it does slow down impulses and messages to areas like the muscles. MS is a much slower acting disease than ALS and individuals may have to deal with mild symptoms for years before things get worse.

Unlike ALS, MS is not normally fatal, but it can suddenly progress quickly, causing loss of muscle strength, requiring the need for full-time care.

ALS vs MS: Symptoms

Signs and symptoms

The symptoms associated with ALS will include muscle cramps, difficulty walking and a tendency to fall. Weakness might show itself in the extremities like the hands (especially in the initial stages) and there can often be a good deal of clumsiness when handling simple manual tasks like button up a shirt.

With MS, an individual might experience tingling or numbness, there can be blurring of vision and bouts of dizziness. The condition also has an effect on areas like sexual function and bowel movement. Changes in mood can be a factor as well.

ALS vs MS: Memory vs cognition

Both conditions can have an impact on memory and normal cognitive processes, but MS seems to have the more profound effect. Those with MS tend to experience more severe bouts of depression, mood swings and a decreased ability to multi-task.

ALS vs MS: Other differences

MS is classed as an autoimmune disease which is where the immune system is essentially tricked into attacking a healthy part of the body, in this case, the brain and central nervous system.

ALS is, on the other hand, classed as a nervous system disorder and the immune system is not playing a part. In truth, the definitive causes of ALS are not yet known, though various theories have been put forward including a gene mutation, previous nerve damage, as well as a chemical imbalance in the body.

  • ALS is far rarer than MS. Around the US, it’s estimated there are over 400,000 people with MS. That’s compared to 30,000 people dealing with ALS.
  • There is a gender difference between the two. 20% more men get ALS than women and 2-3 more women get MS than men.
  • Each condition typically tends to be diagnosed in individuals at different ages. MS is normally diagnosed between 20 and 50. ALS generally affects older people, between 40 and 70.
  • An electromyography or nerve speed test will be carried out to diagnose ALS.
  • An MRI scan is used for MS as it can detect the demyelination that occurs during the disease.


The differences between ALS and MS become more apparent the closer that you look at the two diseases. While they share some common attributes as neurodegenerative diseases, they work through different mechanisms and have significantly different effects and outcomes on the human body.