What causes fatigue?
Many conditions, disorders, medications and lifestyle factors can cause fatigue. Fatigue can be temporary, or it can be a chronic condition (lasting six months or more). You may be able to relieve your symptoms by changing your diet, medications, exercise or sleep habits. If an underlying medical condition causes fatigue, doctors can usually treat the condition or help you manage it.
Causes of fatigue include:
- Lifestyle habits: Poor diet, excessive alcohol, drug use, too much stress and a sedentary lifestyle can all contribute to fatigue. Jet lag commonly causes temporary fatigue (symptoms usually improve in a few days).
- Medical conditions: Fatigue is a symptom of a wide range of diseases, disorders and deficiencies affecting various parts of the body.
- Sleep disorders: Insomnia, sleep apnea, and narcolepsy can cause extreme exhaustion and long-term fatigue.
- Medications and treatments: Several prescription and over-the-counter drugs, including antihistamines and blood pressure medications, can cause fatigue. Fatigue is a common side effect of bone marrow transplants, chemotherapy and treatments for a range of conditions.
What medical conditions cause fatigue?
Hundreds of conditions and disorders lead to fatigue. Some of the most common causes of fatigue include:
- Disease and infection: Cancer, kidney disease and multiple sclerosis are just a few diseases that cause fatigue. Fatigue can also be a sign of infections such as mononucleosis, HIV and flu.
- Mental health conditions: Fatigue from depression or anxiety may make it difficult or impossible to perform daily activities.
- Autoimmune disorders: Fatigue is a symptom of many autoimmune diseases, including diabetes, lupus and rheumatoid arthritis.
- Hormonal imbalances: Problems with your endocrine system (the glands in your body that make hormones) can lead to exhaustion. Hypothyroidism is a common cause of fatigue.
- Chronic conditions: Chronic fatigue syndrome (also called CFS or myalgic encephalomyelitis) and fibromyalgia cause severe, long-lasting fatigue.
- Heart and lung problems: Fatigue is a common symptom of cardiovascular conditions such as heart disease, postural orthostatic tachycardia syndrome (POTS), chronic obstructive pulmonary disease (COPD), emphysema and congestive heart failure.
- Deficiencies: Anemia and other vitamin deficiencies (such as vitamin D or vitamin B12) are often responsible for fatigue. Dehydration can cause fatigue because the body needs plenty of fluids to function.
- Weight problems and eating disorders: Anorexia, bulimia, obesity or being underweight can lead to fatigue and a range of other symptoms.