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What are Common Causes of Muscle Weakness and Fatigue?

Alex Paul
Alex Paul

Muscle weakness and fatigue are actually two different conditions, although they can be caused by similar problems in some cases. There are a large number of potential causes of these symptoms, including disease, a muscle pull or tear, and overuse. A lack of certain minerals in the body, muscle wastage due to lack of use, and nervous system conditions may also lead to these problems. In some cases, muscle fatigue may simply be caused by insufficient sleep or exhaustion, although long-term symptoms may be a sign of something more serious.

Weakness occurs when the muscle isn’t able to provide its normal strength. This commonly occurs, for example, after a long workout in which the muscle becomes sore or tired for a period of time. This usually goes away naturally once the muscle has had time to recover.

In some cases, chronic fatigue syndrome may be the cause for someone's lack of energy.
In some cases, chronic fatigue syndrome may be the cause for someone's lack of energy.

True muscle weakness, where the muscle becomes permanently weak, is a more serious condition. If a muscle gets gradually weaker over time, this can be a sign of a number of health problems, including an impairment in the nervous system that affects the signals to the muscle, diseases such as celiac disease, and conditions such as fibromyalgia. In most cases, a gradual weakening of a muscle that’s being regularly used is cause for a visit to a medical professional for an evaluation.

Fatigue is commonly caused by overwork.
Fatigue is commonly caused by overwork.

Muscle weakness and fatigue, although similar, have noticeably different symptoms. Fatigue is when the muscles feel tired or lack energy. This can be caused by the person being overworked, not getting enough sleep, or general health problems, such as the common cold. Usually, fatigue will disappear when the problem is rectified. If it doesn’t get better within a couple of weeks, however, the individual should see a healthcare professional.

Dehydration and lack of proper nutrition can cause muscle weakness all over the body.
Dehydration and lack of proper nutrition can cause muscle weakness all over the body.

Some of the most serious causes of muscle problems include a disease that affects the liver or kidneys, diabetes, or heart failure. Any condition that limits the blood flow to the muscles can cause a feeling of weakness. Issues with the thyroid are also known to cause weakness and fatigue.

Both chronic fatigue syndrome and fibromyalgia can cause these types of symptoms. These conditions can be difficult to diagnose, so the weakness may be present for a long time before its cause is determined.

Discussion Comments

kylee07drg

@giddion – Overusing your muscles can make you feel like you've been hit by a truck. I felt this way after going hiking uphill. I couldn't walk for days!

There have been times when my muscles have felt weak and I haven't actually done anything, though. Changing my diet a little fixes this.

Eating a banana every day has helped keep my muscles in good condition. Drinking lots of water keeps them from getting cramps, that can make them feel fatigued.

Oceana

One cause of fatigue and weakness is the flu. I know I'm coming down with it when I feel achy all over for no reason and I start to develop a fever.

A cold usually doesn't cause this. The flu always makes me feel like I've run for miles when I haven't done anything other than sit at my desk all day, though.

giddion

I have experienced extreme muscle fatigue before, and it makes my muscles very weak for a short time. This has happened to me several times after a few hours of gardening.

It happens more often in the spring, when my body hasn't had time to adjust to my new gardening schedule. It's coming out of a winter of rest, so the sudden work comes as a shock to my muscles.

For about two or three days following my work, I get so sore that I can barely get out of bed. My legs shake and it's hard to stand up, let alone walk.

I can forget about doing any sort of yard work when my muscles get like this. I need about a week to recover, and then I gradually get back into it.

Kristee

Fibromyalgia and fatigue go hand in hand. I have a friend with this condition, and she is super tired almost all the time.

She doesn't even have to do much to feel tired. She says that her muscles and skin ache, and though she sleeps, she never feels rested.

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    • In some cases, chronic fatigue syndrome may be the cause for someone's lack of energy.
      By: karuka
      In some cases, chronic fatigue syndrome may be the cause for someone's lack of energy.
    • Fatigue is commonly caused by overwork.
      By: Picture-Factory
      Fatigue is commonly caused by overwork.
    • Dehydration and lack of proper nutrition can cause muscle weakness all over the body.
      By: Ambrose
      Dehydration and lack of proper nutrition can cause muscle weakness all over the body.
    • A child suffering from fatigue and weakness may be susceptible to falls.
      By: ivolodina
      A child suffering from fatigue and weakness may be susceptible to falls.
    • Celiac disease could be the cause of gradual muscle weakening over time.
      By: joshya
      Celiac disease could be the cause of gradual muscle weakening over time.