Fatigue is a term used to describe an overall feeling of tiredness or lack of energy. It isn’t the same as simply feeling drowsy or sleepy. When you’re fatigued, you have no motivation and no energy. Being sleepy may be a symptom of fatigue, but it’s not the same thing.
Fatigue is a common symptom of many medical conditions that range in severity from mild to serious. It’s also a natural result of some lifestyle choices, such as lack of exercise or poor diet.
If your fatigue doesn’t resolve with proper rest and nutrition, or you suspect it’s caused by an underlying physical or mental health condition, see your doctor. They can help diagnose the cause of your fatigue and work with you to treat it.
Types of fatigue
There are two main types of fatigue: physical and mental.
A person with physical fatigue may find it physically hard to do the things they usually do, such as climbing the stairs. Symptoms include muscle weakness, and diagnosis may involve completing a strength test.
With mental fatigue, a person may find it harder to concentrate on things and stay focused. They may feel sleepy or have difficulty staying awake while working.
Is it sleepiness or fatigue?
Sleepiness can occur when a person does not get enough good quality sleep, or when they have a lack of stimulation. It can also be a symptom of a health condition that interferes with sleep, such as sleep apnea or restless legs syndrome.
Sleepiness is more likely to be short-term than fatigue. It is usually treatable with regular and consistent sleep.
However, fatigue — especially when it is chronic — is often associated with a health condition or problem. It may also be its own chronic condition, called chronic fatigue syndrome, or myalgic encephalomyelitis.
Causes of fatigue
Fatigue is associated with many health conditions and lifestyle factors. The sections below will outline these in more detail.
Mental health issues
Fatigue is a common symptom of clinical depression, either due to the depression itself or associated problems, such as insomnia.
Fatigue can also result from the following mental health issues:
- bereavement and grief
- eating disorders
- emotional exhaustion or burnout
- life events, such as moving home or getting a divorce
Endocrine and metabolic reasons
Health conditions and other factors that affect hormones can cause fatigue. These include:
- Cushing’s syndrome
- kidney disease
- electrolyte problems
- thyroid conditions
- hormonal contraception, including birth control pills and the implant
Drugs and medications
Certain drugs and medications can cause fatigue. These include:
- some antidepressants
- anxiety medications
Medication withdrawal can also cause fatigue until the body adjusts. Changes in dosage can also be a cause.
When is it time to see your doctor?
You should make an appointment with your doctor if you’re feeling fatigued and you:
- can’t think of anything that might account for your fatigue
- have a higher-than-normal body temperature
- have experienced unexplained weight loss
- feel very sensitive to colder temperatures
- regularly have trouble falling or staying asleep
- believe you may be depressed
If you’ve made efforts to address the most common lifestyle causes, such as lack of rest, poor eating habits, and stress, without success, and your fatigue has continued for two weeks or more, make an appointment with your doctor.
In some cases, your fatigue might be caused by a serious medical condition. Go to the hospital immediately if you experience fatigue along with any of the following symptoms:
- rectal bleeding
- vomiting blood
- severe headache
- pain in your chest area
- feelings of faintness
- irregular heartbeat
- shortness of breath
- severe pain in your abdominal, back, or pelvic region
- thoughts of suicide or self-harm
- thoughts of harming another person
How will your doctor treat fatigue?
Your doctor’s recommended treatment plan will depend on what’s causing your fatigue. To make a diagnosis, they will likely ask you questions about:
- the nature of your fatigue, including when it started and whether it gets better or worse at certain times
- other symptoms that you’ve been experiencing
- other medical conditions that you have
- your lifestyle and sources of stress
- medications that you’re taking
If your doctor suspects you have an underlying medical condition that’s causing your fatigue, they may order some medical tests. For example, they may order blood or urine tests.
A range of health conditions and lifestyle factors — such as diabetes, depression, and chronic pain, among others — can lead to fatigue.
If fatigue and sleepiness are affecting a person’s daily life and none of the tips in this article work, they should see a doctor for advice.
To help with diagnosis, a person can keep a diary of their sleep habits and symptoms. After making a diagnosis, a doctor will be able to suggest some appropriate treatment options.