Muscle weakness is a generalized feeling that the muscles do not feel like they are performing to their usual ability. This can have a wide range of presenting symptoms, but for many, muscle weakness is noticeable and due to many factors. Let’s take a close look at muscular weakness and fatigue and some reasons it can affect your body.
What is the Difference Between Muscle Weakness and Fatigue?
While these two are very similarly grouped and have similar outcomes, they are quite different. In a general sense, muscle fatigue is something that occurs when the muscle or muscle groups become tired, usually during or after an activity. Some people might notice this during exercise, when performing daily tasks, or simply walking around. If muscle fatigue affects you, take note of how you feel to see what a cause might be.
In comparison, muscle weakness is something that occurs when a certain part of your body is unable to perform a usual movement. This could be something as easy as lifting a carton of milk, raising your arm to reach in the pantry, or standing up from a seated position. In muscle weakness, the muscle or muscle group affected could decrease your ability to do daily tasks and it could cause muscle imbalances elsewhere as well.
It can be difficult to determine which type of muscle condition is affecting you and sometimes a physiotherapist or doctor can help to better assess which you are experiencing.
What Can Cause Muscle Weakness?
Finding a cause of muscle weakness can be important so that therapy can help to prevent any further weakness. Listed below are some causes of muscle weakness.
Heart Disease.
Heart disease is the single most common condition to affect adults worldwide, causing roughly 19 million deaths in 2020 alone. When the heart muscle does not pump blood to the body correctly, it could cause a feeling of generalized fatigue and muscle weakness. If you suspect you have heart disease and have been experiencing muscle weakness, consider seeing your doctor about your symptoms.
Sedentary Lifestyle.
One common lifestyle factor that is becoming more common over the years is sedentary behavior. This type of behavior is usually due to working in front of a computer, sitting for long periods of time during the day, and having no energy to exercise. Your muscles are very adaptive and when they are not used, muscle mass can diminish. When muscle mass becomes diminished, weakness is likely to show at some point. Living an active lifestyle is important for many ways but having a sound exercise routine to work as many muscle and muscle groups as possible is important to prevent any muscular loss.
Increasing Age.
One of the most inevitable things in life is that we are all getting older. The aging process can contribute to muscle weakness throughout the years and can play a role in building back muscle as well. Studies have shown building muscle after the age of 60 years becomes more difficult and this brings importance to once you lose muscle you lose it. When adults are in their 20s or 30s, muscle mass is not lost quite as easily. However, as we continue to age, the muscle that we can build and maintain becomes steadily lower. This underscores the importance of a resistance training program and why an active lifestyle is so valuable.
Illnesses.
If you experience muscle weakness or fatigue and have been feeling under the weather, then chances are your symptoms are due to an illness. Common illnesses that can cause weakness and fatigue are the common cold, influenza (flu), vital infections, sinus infections, and more. If you feel ill and have generalized muscle weakness, consider seeing a doctor so that you can get the proper treatment and to ensure there isn’t more affecting your health.
Long-Term Conditions.
Chronic conditions can be a major reason to have muscle weakness or fatigue. Between taking medication and the actual disease processes, muscle weakness is common. Consider some of the following chronic conditions that could cause muscle weakness and fatigue.
- Diabetes.
Some people acquire diabetes at a young age, but many adults acquire this condition in middle age. Current estimates suggest about 537 million people 20-79 years of age have diabetes and this condition can affect the nerves and blood flow to the extremities of the body. When this happens, muscles might not function as efficiently as they once did and weakness could result.
- Kidney Disease.
The kidneys’ main function in the body is to filter out waste from the blood. When kidney disease occurs, it means the kidneys are most likely not filtering out this waste efficiently and, in some cases, not at all. When waste builds up, it can lead to generalized fatigue, muscle weakness, and other symptoms.
- Anemia.
Proper blood flow is important for maintaining energy levels and muscular health. When blood flow is interrupted either from fast moving blood or too slow, this can cause fatigue to set in. In the setting of anemia, there are too few red blood cells circulating, which can cause blood flow to travel faster and cause symptoms of fatigue and muscle weakness. Treatment for this condition is important because it can lead to shortness of breath and excessive tiredness.
- Sleep Apnea.
Sleep is the body’s most basic function, and it is important for various reasons. Proper sleep can help maintain the immune system, recharge the mind, and rebuild damaged cells. In addition, sleep is important for maintaining energy levels. In the case of chronic sleep apnea, your body might not feel rested, muscles could feel weak, and all of this is despite feeling like you sleep well at night. Treating chronic sleep apnea could help manage muscle weakness of this affects you.
- Mental Health Conditions.
Mental health plays a big role in how your muscles work, since nerve cells create the transmission for muscle contractions. When your mind is not at its best such as with depression, anxiety, and other conditions, you’re likely to experience muscular weakness.
Can Medications Cause Muscle Weakness?
Medications are necessary for a wide range of conditions and if you are taking any prescribed medicine, or over the counter drugs, you could have the side effect of muscle weakness as a result. Common medications that could cause muscle weakness includes:
- Chemotherapy- pills or infusions
- Steroids
- Statins and heart medicine
- Medicine for overactive thyroid function
- Some pain killers
Alcohol, Smoking, and Recreational Drug Use
The ill effects of smoking, drinking, and drug use have been commonly described as more research is performed. Alcohol in small or large quantities can cause muscular issues, including twitching, weakness, and fatigue. In addition, smoking can cause narrowing of the blood vessels in the heart and entire body, which decreases the amount of nutrients reaching the working muscles. Recreational drug use such as marijuana, cocaine, and methamphetamine can cause multi-organ problems that can lead to muscular issues. Consider seeking help if any of these conditions affect you.
What Neurological Conditions Cause Muscle Weakness?
There are a number of neurologic conditions that can directly affect the muscles in the body. Some of these conditions include:
- Fibromyalgia. This is a condition in which the muscles can feel and be weak in addition to having pain, tenderness, and fatigue. The pain that is associated with fibromyalgia can cause muscle weakness and general body fatigue.
- Multiple Sclerosis. This is a condition in which the nerves become inflamed and can lead to progressive muscle loss.
- Parkinson’s Disease. This is a progressive disease in which the brain function decreases and can lead to muscle tremors and rigidity.
- Guillain-Barre Syndrome. This condition causes acute loss of muscle function and can sometimes be a side effect of illnesses or medications.
- Stroke. This is a life-threatening condition that can cause paralysis on one side of the body, and it can lead to muscle weakness and fatigue despite treatment and medical care.
- Myasthenia Gravis. This nerve condition can cause extreme fatigue with delayed recovery times that can be concerning. Usually, muscle fatigue and weakness occur rapidly and the delayed recovery can be extreme for some patients.
When to See A Doctor?
Generalized muscle weakness and fatigue might not be an alarming issue, but if it is chronic, affecting daily life, or is getting worse, it might be time to see a doctor.
Your doctor will likely order blood tests, perform a physical examination, and might have you follow with a neurologist. A neurologist will likely test your reflexes, muscular strength, tone, and possibly perform muscle tests to see if weakness is in one area or the entire body. In some cases, you might need to have a muscle biopsy or MRI imaging to assess further.
If muscle weakness or fatigue is something that affects you it is important to discuss and consult with your doctor for more information. If you are taking medication that is causing you to have these side effects as well, consider asking if there is any alternative so that you can improve your overall daily life.
References
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2804956/
