Fatigue and Tiredness: Common Causes and When to See a Provider

What it involves

MedlinePlus describes fatigue as a feeling of weariness, tiredness, or lack of energy that can interfere with your usual daily activities. It says fatigue is a symptom, not a disease, and that it can be a normal response to physical activity, emotional stress, boredom, or lack of sleep. If you have felt tired for weeks, MedlinePlus advises contacting your health care provider to help find the cause.

Who this is for

• Adults who have felt tired for several weeks and are not sure whether it is sleep, stress, or something else
• Patients whose tiredness began after a new medicine, an illness, or a change in routine
• Patients with diabetes, thyroid, heart, kidney, or liver conditions who notice their energy changing
• Patients who want blood work ordered and each result explained in plain words

What to expect

• Questions about your sleep, daily activities, appetite, and exercise, the same areas MedlinePlus says a provider asks about
• A physical exam and a review of every medicine and supplement you take
• Blood tests when your provider thinks they will help, with each result explained afterward
• A plan for the next step, which may be a repeat visit, more tests, or changes to your routine

Fatigue is a symptom, not a diagnosis

MedlinePlus says fatigue itself is not a disease and can have many different causes, including pregnancy, medical problems, treatments, and lifestyle habits. That is why a visit starts with questions and not with one test. The goal is to sort the likely causes into groups, work through the most probable ones first, and avoid ordering tests that do not fit your story. Feeling run down with a general ill feeling, headache, or fever before a painful one-sided rash appears can be an early stage of shingles, as the shingles guide explains.

Medical problems on MedlinePlus's list

MedlinePlus groups the medical causes of fatigue like this: Anemia is on that list, and the anemia and low iron guide explains the symptoms, causes, and blood tests that separate it from other reasons for tiredness. Tiredness that comes with weight loss you did not plan is worth raising together, and the unintentional weight loss guide explains what counts as a significant drop.

• Long-lasting diseases such as diabetes, COPD, and heart, liver, kidney, and thyroid disease
• Anemia and infections
• Sleep apnea and other sleep disorders
• Untreated pain and conditions such as fibromyalgia
• Mental health conditions such as depression and anxiety

Medicines and habits that drain energy

MedlinePlus says certain medicines can cause fatigue, naming some antidepressants, antihistamines, and medicines for nausea and pain. It also lists habits such as not getting enough sleep, staying up too late, drinking too much alcohol, substance use, caffeine that keeps you from sleeping well, and getting too little or too much exercise. Bring every medicine and supplement to the visit, and do not stop any of them on your own. Unusual tiredness with heavy sweating and thirst after time outdoors may be a heat illness rather than ordinary fatigue, and the heat exhaustion and heat stroke guide lists the signs.

Blood tests that may be part of the picture

MedlinePlus says a provider will likely do a physical exam and order lab tests. Depending on your history, that could include a complete blood count to look for anemia, thyroid blood tests, a vitamin D and B12 check, or a basic metabolic panel that covers blood sugar, kidney numbers, and electrolytes. Nobody needs every test. If blood sugar is the question, the prediabetes A1C range guide explains the numbers.

Keep a fatigue diary

MedlinePlus suggests keeping a fatigue diary to find patterns through the day, such as when you feel more tired and when you have more energy, and to plan activities around the times you feel strongest. Write down bedtime and wake time, caffeine, alcohol, meals, new medicines, and mood. A week or two of notes gives your provider more to work with than a general feeling of being worn out. If poor sleep is the likely reason you are tired, the insomnia and sleep problems guide explains the sleep diary that NHLBI describes.

When tiredness points to something specific

MedlinePlus separates ordinary tiredness that eases with rest from the overwhelming fatigue of myalgic encephalomyelitis/chronic fatigue syndrome, which lasts a long time, does not get better with rest, and limits ordinary daily activities. Tiredness that comes with chest pain or a racing heart is a different visit; the chest pain guide and the palpitations page explain when to call 911 and when to book. Waking unrefreshed and sleepy all day can be a sign of sleep apnea, which the sleep apnea guide explains, including how a sleep study confirms it.

Sources

• MedlinePlus — Fatigue