Muscle weakness: 10 main causes and what to do

Muscle weakness is more common after making a lot of physical effort, such as lifting a lot of weight in the gym or repeating the same task for a long time and usually tends to be more localized, appearing in the legs, arms or chest, depending of the muscles that were being used.

This is because muscle fibers are injured and need to recover, making it harder to have strength. In these cases, the rest of the affected muscles usually relieves the weakness and gives more disposition. Thus, it is very important to avoid training the same muscle two days in a row at the gym, for example, so that the muscle has time to recover.

However, there are other causes that can also cause muscle weakness, such as the cold, which causes a feeling of weakness in all muscles in the body. And while most causes are mild, there are also more serious cases that need to be evaluated by a doctor, especially if the weakness lasts more than 3 to 4 days.

1. Lack of physical exercise

When a person does not do any kind of physical activity and sits for a long time at work, or at home watching television, for example, their muscles will lose strength, as they are not being used. This is because the body begins to replace muscle fibers with fat and, therefore, the muscle is less able to contract.

In addition to physical inactivity, this cause is also very common in the elderly and people who have been bedridden and, in addition to weakness, there is also a tendency to decrease muscle volume and difficulty doing activities that were easy.

What to do: Whenever possible, it is important to do physical activity such as walking, running or weight training at least 2 to 3 times a week. In the case of bedridden people, it is also important to exercise in bed to keep your muscles healthy. Check out some examples of exercises for bedridden people.

2. Natural aging

Over the years, muscle fibers lose their strength and become more flabby, even in the elderly who exercise regularly. This can cause a feeling of generalized weakness, which appears slowly with age.

What to do: maintain the practice of physical exercise, making only the efforts allowed by the body itself. At this stage, it is also important to combine training days with a day of rest, as the body needs more time to recover and avoid injuries. See the most recommended exercises for seniors.

3. Lack of calcium and vitamin D

Calcium and vitamin D are two very important minerals to ensure the correct functioning of muscles, so when your levels are very low you can feel constant muscle weakness, in addition to other symptoms such as muscle spasms, lack of memory, tingling and irritability easy.

What to do: vitamin D is produced in the body itself and through regular sun exposure it is activated and starts to work. Calcium, on the other hand, can be absorbed from some foods such as milk, cheese, yogurt, broccoli or spinach. If these two minerals are at low levels, it may be necessary to take medications prescribed by the doctor.

See also a more complete list of calcium-rich foods.

4. Colds and flu

Widespread muscle weakness and excessive tiredness are very common symptoms of colds and flu and happen because the body is trying to fight the flu virus, so there is less energy available for the correct functioning of muscles. In addition, in some cases, the muscles may also become inflamed due to increased body temperature, which is why the weakness may be more severe in some people.

In addition to the flu, any other infection of the body with viruses or bacteria, can also cause this type of symptoms especially in cases of diseases such as hepatitis C, dengue, malaria, tuberculosis, HIV or Lyme disease.

What to do: if you suspect the flu or cold, you should stay at home, drink plenty of water and rest, avoiding more intense activities, such as going to the gym, for example. If the weakness does not improve, or if high fever and other symptoms appear that may indicate a more serious problem, it is important to go to the general practitioner to identify the cause and start the appropriate treatment.

5. Use of antibiotics

The use of some antibiotics, such as Ciprofloxacin or Penicillin, and other medications such as anti-inflammatory drugs or medicines for high cholesterol, can have side effects such as the appearance of tiredness and muscle weakness.

What to do: consult the doctor who prescribed the medication to evaluate the possibility of changing the medicine. Especially in the case of antibiotics, treatment should not be interrupted without talking to the doctor first.

6. Anemia

Anemia is one of the main causes of the appearance of excessive tiredness, however, when it is more severe, it can also cause muscle weakness, making it more difficult to move your arms and legs, for example. This is because the value of red blood cells is very low and therefore there is less transport of oxygen to the muscles.

What to do: anemia is more common in pregnant women and people who do not eat meat, so if there is a suspicion of this disease, you should go to the general practitioner to do a blood test and assess the number of red blood cells, starting treatment appropriate. Understand how anemia is treated.

7. Depression and anxiety

Some psychiatric changes can cause very strong physical sensations, especially in energy and disposition levels. In the case of depression, it is common for the person to feel low on energy and therefore may experience a lot of muscle weakness throughout the day.

In the case of anxiety sufferers, for example, adrenaline levels are always very high and the body gets more tired over time, resulting in excessive weakness.

What to do: a psychologist and a psychiatrist should be consulted to assess if there are any psychiatric problems that need to be treated with psychotherapy or medication, such as Fluoxetine or Alprazolam.

8. Diabetes

Diabetes is a disease characterized by an increase in blood sugar levels, and when this happens, the muscles are unable to function properly, so it is possible to feel a decrease in strength. In addition, when the amount of sugar is very high, the nerves can begin to suffer injuries, failing to properly enervate some muscle fibers, which end up atrophying.

Generally, the person with diabetes also has other symptoms such as exaggerated thirst, dry mouth, frequent urge to urinate and wounds that take time to heal. Take our test to find out what your risk of diabetes is.

What to do: go to the general practitioner or endocrinologist who can order tests to evaluate blood sugar levels. If there is diabetes, or increased risk, it is important to avoid the consumption of sugary foods and to do the treatment recommended by the doctor.

9. Heart disease

Some heart diseases, especially heart failure, cause a decrease in the volume of blood that is circulating in the body and, therefore, there is less oxygen available to distribute. When this happens, the muscles are unable to contract properly, so it becomes more difficult to do activities that were once simple, such as climbing stairs or running.

These cases are more common after the age of 50 and are accompanied by other symptoms such as feeling short of breath, swelling in the legs, palpitations or frequent coughing, for example.

What to do: If heart disease is suspected, it is important to consult a cardiologist for tests, such as electrocardiogram and echocardiogram, in order to identify if there are any changes that require specific treatment.

10. Breathing problems

People with respiratory problems, such as asthma or pulmonary emphysema, for example, may suffer more often from muscle weakness. This is because oxygen levels are generally lower than normal, especially during or after a crisis. In these cases, the muscle receives less oxygen and, therefore, is not as strong.

What to do: keep the treatment recommended by the doctor and rest when muscle weakness appears. People who do not have respiratory problems, but who are suspicious, should consult a pulmonologist to carry out the necessary tests and initiate appropriate treatment.