• Sat. Apr 30th, 2022

Amyotrophic lateral sclerosis(ALS) and its symptoms, causes, risk factor, and Complications

Amyotrophic lateral sclerosis(ALS)

Amyotrophic lateral sclerosis (ALS)

Amyotrophic lateral sclerosis (ALS) is a degenerative disease that impacts the brain and spinal cord. ALS loses spontaneous muscle control, which worsens over time. It affects movements such as speaking, walking, and swallowing.

Unfortunately, no cure has been found so far. But some treatments can reduce the symptoms and help people with ALS live longer.

Famous baseball player Lou Kehrik developed the symptoms of this condition in the 1930s, which is why it is also known as Lou Kehrik disease.


Symptoms of ALS vary greatly, from person to person, depending on which neurons are affected. It usually starts with muscle weakness that spreads and gets worse over time. Symptoms might include:

  • Hand weakness or clumsiness
  • Difficulty walking or doing normal daily activities
  • Weakness in your legs, feet, or ankles
  • Tripping and falling
  • Slurred speech or trouble swallowing
  • Muscle cramps and twitching in your arms, shoulders, and tongue
  • Inappropriate crying, laughing, or yawning
  • Cognitive and behavioral changes

ALS often starts in the hands, legs, or limbs and spreads to other parts of your body. As the disease advances and nerve cells are destroyed your muscles become weaker. It eventually affects chewing, swallowing, speaking, and breathing.

There’s generally no pain in the early stages of ALS, and pain is uncommon in the later stages. ALS usually does not affect your bladder control or your senses.


ALS impacts the nerve cells that control voluntary muscle movements such as talking and walking (motor neurons). ALS causes motor neurons to gradually deteriorate and then die. Motor neurons expand from the brain to the spinal cord to the muscles throughout the body. When motor neurons are harmed, they stop sending messages to the muscles. So the muscles cannot function.

ALS is inherited in 5% to 10% of the population. For the rest, the cause isn’t known.

Researchers are constantly exploring the possible causes of ALS. Most theories focus on the complex relationship between genetic and environmental factors.

Risk factors

Established risk factors for ALS include:

  • Heredity. Five to 10% of the people with ALS inherited it (familial ALS). In most people with familial ALS, their children have a 50-50 chance of creating the disease.
  • Age. The risk of ALS increases with age and is most common in the 40 and mid-60s.
  • Sex. Before the age of 65, men develop slightly more ALS than women. This gender difference will disappear after the age of 70.
  • Genetics. Some studies of the entire human genome have found similarities between the genetic variants of those with familial ALS and the genetic variants of some with non-hereditary ALS. These genetic variants make people more susceptible to ALS.

Environmental factors, such as the following, might trigger ALS.

  • Smoking. Smoking is the only potential environmental risk factor for ALS. Women are at higher risk, especially after menopause.
  • Environmental toxin exposure. Some evidence suggests that exposure to lead or other substances in the workplace or at home may be associated with ALS. A lot of research has been done, but no one agent or chemical has been consistently associated with ALS.
  • Military service. Studies show that those who serve in the military are more likely to be affected by ALS. It is unclear what military service will drive the growth of ALS. These include certain metals or chemicals, traumatic injuries, viral infections, and intense labor.


As the disease progresses, ALS causes complications, including:

Breathing problems

Over time, ALS paralyzes the muscles you use to breathe. You may need a device to help you breathe at night, just like wearing a person with sleep apnea. For example, you may be given a Bile Level Positive Air Pressure (BiPAP) device to help you breathe at night. This type of device supports your breathing through a mask worn on your nose, mouth, or both.

Some people with advanced ALS opt for a tracheostomy, a surgical incision made in the front of the neck leading to the trachea (trachea) – to lift and ventilate their lungs for full-time use of a respirator.

The most common cause of death for people with ALS is respiratory problems. On average, death occurs within 3 to 5 years of the onset of symptoms. However, some people with ALS live for 10 or more years.

Speaking problems

Most people with ALS have trouble speaking. It usually starts with the occasional, mild blur of words, but becomes more intense. Speech eventually becomes difficult for others to understand, and people with ALS rely on other communication technologies to communicate.

Eating problems

In people with ALS, damage to the muscles that control swallowing can lead to malnutrition and dehydration. Food, fluids, or saliva are at high risk of entering the lungs, which can cause pneumonia. A feeding tube will reduce these risks and ensure proper hydration and nutrition.


Some people with ALS have problems with memory and decision making, and some eventually develop a type of dementia called frontotemporal dementia.