Most of the time fatigue can be traced to one or more lifestyle issues, such as poor sleep habits or lack of exercise. Fatigue can be caused by a medicine or linked to depression. Sometimes fatigue is a symptom of an illness that needs treatment.

Lifestyle factors

Fatigue may be related to:

• Alcohol or drug use
• Eating poorly
• Medicines, such as ones used to treat allergies or coughs
• Not enough sleep
• Too little physical activity
• Too much physical activity

Conditions

Exhaustion that doesn't let up might be a sign of:

• Adrenal insufficiency
• Amyotrophic lateral sclerosis (ALS)
• Anemia
• Anxiety disorders
• Cancer
• Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS)
• Chronic infection or inflammation
• Chronic kidney disease
• COPD
• Coronavirus disease 2019 (COVID-19)
• Depression (major depressive disorder)
• Diabetes
• Fibromyalgia
• Grief
• Heart disease
• Heart failure
• Hepatitis A
• Hepatitis B
• Hepatitis C
• HIV/AIDS
• Hyperthyroidism (overactive thyroid) also known as overactive thyroid.
• Hypothyroidism (underactive thyroid)
• Inflammatory bowel disease (IBD)
• Liver disease
• Low vitamin D
• Lupus
• Medicines and treatments, such as chemotherapy, radiation therapy, pain medicines, heart medicines and antidepressants
• Mononucleosis
• Multiple sclerosis
• Obesity
• Parkinson's disease
• Physical or emotional abuse
• Polymyalgia rheumatica
• Pregnancy
• Rheumatoid arthritis
• Sleep apnea — a condition in which breathing stops and starts many times during sleep.
• Stress
• Traumatic brain injury

Call 911 or your local emergency number

Get emergency help if you have fatigue and any of the following:

• Chest pain.
• Shortness of breath.
• Irregular or fast heartbeat.
• Feeling that you might pass out.
• Severe stomach, pelvic or back pain.
• Unusual bleeding, including bleeding from the rectum or vomiting blood.
• Severe headache.

Seek help for urgent mental health problems

Get emergency help if your fatigue is related to a mental health problem and your symptoms also include thoughts of harming yourself or of suicide. Call 911 or your local emergency services number right away. Or contact a suicide hotline. In the U.S., call or text 988 to reach the 988 Suicide & Crisis Lifeline. Or use the Lifeline Chat.

Schedule a doctor's visit

Call for an appointment with a health care provider if resting, reducing stress, eating well and drinking plenty of fluids for two or more weeks hasn't helped your fatigue.