What is weakness?
Weakness is a feeling of being tired or exhausted, or experiencing a loss of strength. Weakness may not always be accompanied by obvious or visible illness. Short-term weakness may occur because of overwork, stress, or lack of sleep. You may also feel weakness after overcoming an illness, such as a cold or the flu. Some weakness may occur after vigorous physical activity.
Weakness may occur throughout your entire body or in a specific area, such as your arms or legs. Weakness may also be localized to a single muscle such as a calf muscle in your leg.
You may also feel weakness as a symptom of depression. Depression is defined as feeling blue, miserable or sad. While occasional periods of sadness are normal, long-term depression, called clinical depression, may indicate serious emotional or psychological problems. Weakness or fatigue that is persistent always requires the prompt attention of your health care provider.
Weakness may also occur because of physical diseases or toxic disorders. Long-term (chronic) conditions, such as multiple sclerosis or an underactive thyroid, may cause weakness. Short-term (acute) conditions, such as a pinched nerve or a urinary tract infection, may also cause weakness. Other possible causes of weakness are toxic disorders (botulism), exposure to an insecticide, or shellfish poisoning.
Weakness that is related to an acute condition may require emergency attention. Seek immediate medical care (call 911) if you experience sudden onset of weakness on one side of your body or face; weakness with shortness of breath or palpitations; or weakness with loss of consciousness, severe chest pain, back pain, or abdominal pain. Seek prompt medical care if you have malaise along with other symptoms, such as abdominal pain or cramping, fever and chills, foul-smelling urine, or a general ill feeling.
What other symptoms might occur with weakness?
Weakness may accompany other symptoms that vary depending on the underlying disease, disorder or condition. Weakness that is related to a physical disorder may differ from weakness that is related to an emotional or psychological condition.
Physical symptoms that may occur along with weakness
Weakness may accompany other symptoms affecting the body including:
Abdominal pain or cramping
Bloody or pink-colored urine (hematuria)
Fever and chills
General ill feeling
Loss of appetite
Missed menstrual periods
Other symptoms that may occur along with weakness
Weakness may accompany symptoms related to emotional or psychological disturbance including:
Changes in mood, personality, or behavior
Difficulty with memory, thinking, talking, comprehension, writing or reading
Irritability or mood changes
Malaise or lethargy
Serious symptoms that might indicate a life-threatening condition
In some cases, weakness may be a symptom of a life-threatening condition that should be immediately evaluated in an emergency setting. Seek immediate medical care (call 911) if you, or someone you are with, have any of these life-threatening symptoms including:
- Abdominal, pelvic, or lower back pain that can be severe
- Difficulty speaking or swallowing
- Fainting, change in level of consciousness, or lethargy
- High fever (higher than 101 degrees Fahrenheit)
- Inability to stand
- Incontinence of urine or feces
- Sudden balance problems, difficulty walking, and falls
- Sudden loss of vision or changes in vision
- Sudden weakness or numbness on one side of the body
- Vomiting, including multiple episodes
- Worst headache of your life
What causes weakness?
Weakness is a feeling of being tired, exhausted, or experiencing a loss of strength. Weakness may or may not be accompanied by obvious or visible sickness. Short-term weakness may occur because of overwork, stress, or lack of sleep. You may also feel weakness after overcoming an illness, such as a cold or the flu. It is normal to feel some weakness after some physical activity.
You may also feel weakness as a symptom of depression. Long-term depression may indicate more serious emotional or psychological problems.
Weakness may also occur because of physical diseases or toxic disorders. Long-term (chronic) conditions, such as multiple sclerosis or an underactive thyroid may cause weakness. Short-term (acute) conditions, such as a pinched nerve or a urinary tract infection, may also lead to weakness. Other possible causes of weakness are toxic disorders, exposure to an insecticide, or shellfish poisoning.
Emotional or psychological causes of weakness
Weakness may be caused by emotional or psychological disturbances including:
- Lack of sleep
Physical causes of weakness
Weakness can also be caused by chronic physical disorders including:
Anemia (low red blood cell count)
Cancer and anticancer therapies
Exposure to toxic substances or poisons
Fibromyalgia (chronic condition that causes pain, stiffness and tenderness)
Hashimoto’s thyroiditis (autoimmune disease resulting in hypothyroidism and low production of thyroid hormone)
Hypothyroidism (underactive thyroid)
Infections (Lyme, hepatitis, HIV/AIDS)
Multiple sclerosis (disease that affects the brain and spinal cord causing weakness, coordination, balance difficulties, and other problems)
Muscle breakdown (rhabdomyolysis)
Muscular dystrophy (inherited disorder that causes a progressive loss of muscle tissue and muscle weakness)
Myasthenia gravis (autoimmune disorder that causes a progressive loss of muscle tissue and muscle weakness)
Polymyositis (widespread inflammation and weakness of muscles)
Serious or life-threatening causes of weakness
Arrhythmias (irregular heart beats)
Dehydration (loss of body fluids and electrolytes, which can be life threatening when severe and untreated)
Myasthenia gravis crisis
Myocardial infarction (heart attack)
Myxedema coma (life-threatening complications of hypothyroidism)
Ruptured aortic aneurysm
Sepsis (life-threatening bacterial blood infection)
Toxic ingestion, such as eating poisonous plants, mushrooms or chemicals
Questions for diagnosing the cause of weakness
To diagnose your condition, your doctor or licensed health care provider will ask you several questions related to your weakness including:
How long have you felt weak?
Do you feel weak all over or is it specific to one area of your body?
Do you use alcohol or drugs?
Are you in any physical pain or discomfort?
Do you have any other symptoms?
What medications are you taking?
When did you first notice the feelings of fatigue or depression?
Are you currently under the care of a mental health care professional?
What are the potential complications of weakness?
Because weakness can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care provider design specifically for you to reduce the risk of potential complications including:
- Difficulty performing daily tasks
- Difficulty sleeping
- Inability to work or go to school
- Loss of mobility
- Progression of symptoms
- Spread of cancer
- Spread of infection
- Withdrawal or depression