Fatigue From Medicines, Mood and Other Health Conditions

Why this page exists

Tiredness is often a signal from somewhere else. This page lists contexts a clinician may consider, so you know what to raise. It is not a checklist for diagnosing yourself. Many of these are covered in more depth elsewhere on this site.

Medicines

MedlinePlus lists certain medicines as a cause of fatigue, naming antidepressants, antihistamines, and medicines for nausea and pain. [1] The MedlinePlus encyclopedia also names sedatives. It says some antidepressants may cause or worsen fatigue, in which case a provider may adjust the dose or switch the medicine, and it warns not to stop or change any medicine without first talking to your provider. [2] NHS lists cancer treatments such as chemotherapy among medical treatments that can cause tiredness. [3]

What to do: bring a full list of your medicines and supplements to the appointment, including over-the-counter products. Read Medicines, sleep, mood and memory and How interactions work. Do not add stimulants or "energy" products to counter a medicine's drowsiness without asking, as MedlinePlus says stimulants are not effective treatments for fatigue. [2]

Mood-related fatigue

NHS lists lack of energy, disturbed sleep, no motivation or interest, and moving or speaking more slowly among the symptoms of depression, which can also include anxiety and unexplained aches. It suggests seeing a GP if symptoms last most of the day, every day, for more than 2 weeks. [4] MedlinePlus notes that if you have long-term pain or depression, treating it often helps the fatigue. [2] Anxiety is also listed among mental disorders linked to fatigue. [1]

For more on how stress, anxiety, burnout and depression differ, see Stress, anxiety, burnout and depression and Burnout.

If you have thoughts of harming yourself or suicide, in the US call or text 988 (free, 24/7), or use your local emergency number. MedlinePlus lists thoughts of harming yourself as a reason to contact a provider right away. [2]

Sleep disorders

Sleep apnea, insomnia and narcolepsy can all cause daytime tiredness. [2] NHS says breathing that stops and starts in sleep, gasping or snorting noises, loud snoring, and always feeling very tired in the day are reasons to see a GP, and that sleep apnea can be serious if untreated. [5] See Sleep apnea, Insomnia and Narcolepsy and hypersomnia.

Other health conditions

MedlinePlus lists chronic diseases such as diabetes, COPD, and heart, liver, kidney and thyroid disease, along with untreated pain, fibromyalgia, anemia, infections and recovery from major surgery. [1] NHS lists very tired, very thirsty, peeing more often and weight loss as a pattern worth checking for diabetes. [3] [6] See Prediabetes, type 2 diabetes and metabolic syndrome, Anemia and iron deficiency and Thyroid problems and fatigue.

Long COVID and other infections

NHS describes long COVID as symptoms lasting longer than 12 weeks, with extreme tiredness among the most common. It says tests may include blood tests and checks of heart rate and oxygen levels, that there is no cure but treatment can ease symptoms, and not to restart exercise before talking to a GP or specialist. [7] Glandular fever and COVID-19 are also listed as illnesses that can cause tiredness. [3] See ME/CFS and post-exertional malaise.

Alcohol and substances

Regular alcohol or drug use, especially of drugs such as cocaine or narcotics, can contribute to fatigue. [2] NHS advises not drinking more than 14 units a week on a regular basis and says there is no safe drinking level. [8]

When to get help

Ask for a review if your tiredness started after a new medicine, comes with low mood, or has gone on for weeks. [3] [1] See Fatigue: when to get help.