Why Are You So Tired All The Time? | Get Healthy Stay Healthy

Why Are You So Tired All The Time?

Published on Jul 20, 2018
Medically reviewed by Dipali Davé, MD, MHA
An exhausted young woman standing in front of a yellow background. She is wearing a yellow t-shirt, holding a large takeaway coffee in one hand, and resting her head in her other hand.

Everyone gets tired from time to time. But some people can feel exhausted over a long period of time, even with enough rest. Extreme tiredness (or fatigue) describes a physical or mental state of being tired and weak. It can affect your energy level, your ability to carry out normal everyday tasks, and your mood.

Fatigue is not usually a serious issue. But sometimes, it can be a sign of a medical problem that you need to get checked out. Learn more about some possible causes of fatigue.

Lifestyle Causes of Fatigue

Fatigue can result from lots of common behaviors or problems such as:

  • Poor Sleep: A lack of sleep can take a toll on your body, leaving you rundown and exhausted. It is recommended that adults get at least 7 hours of sleep, if not more every night on a regular basis to promote optimal health.
  • Too Much Alcohol or Caffeine: Alcohol can initially make you drowsy, but in most cases it can cause you to wake up at night, which can lead to fatigue. Caffeine is often used to increase concentration, but too much can disrupt a good night of sleep. Try to limit alcohol and caffeine intake in the evening prior to bedtime.
  • Taking Medications: Certain medicines, such as blood pressure medications, antidepressants, or antihistamines, are commonly associated with fatigue.
  • Unbalanced Diet: A poor diet or even not eating enough can make you feel sluggish. Nutrition-dense foods can help to provide adequate energy and ward off fatigue.

You may find that changing your habits can help you feel more energized. But if that doesn’t work, talk to your doctor. You could have an underlying problem that needs treatment.

Conditions That Can Cause Fatigue

Fatigue is associated with many health conditions or diseases. Some of these can include:

  • Chronic fatigue syndrome (CFS): This is a long-lasting and complex condition where people experience extreme fatigue that does not get better with bed rest. The exhaustion can be so overwhelming that you may struggle with everyday activities—like getting dressed or taking a shower. Along with fatigue, you may also notice weakness, joint and muscle pain, unrefreshing sleep, and trouble concentrating.
  • Thyroid disorder: The thyroid gland produces hormones that help control your breathing, heart rate, body temperature, digestion, and other body functions. If your thyroid starts to make too much thyroid hormone (hyperthyroidism), many body functions speed up. If your thyroid doesn’t make enough thyroid hormone, body functions may slow down (hypothyroidism). Either condition can leave you feeling tired and fatigued.
  • Depression: Everyone feels unhappy and anxious sometimes, but usually those feelings go away on their own. Depression is different. It’s a serious mood disorder—affecting around 1 million Australians and around 640,000 New Zealanders in any given year—that can cause ongoing sadness and hopelessness. While the symptoms of depression are different for everyone, many people experience fatigue and changes in their sleep patterns.
  • Anaemia: Red blood cells in your blood have an important job: they help carry oxygen from the lungs to the rest of your body. When you don’t have enough healthy red blood cells, your body can’t get enough of the oxygen-rich blood it needs. This problem is called anaemia, and some types of anaemia are common. It can leave you feeling constantly tired and weak. You may also feel dizzy and find it hard to catch your breath.
  • Sleep apnoea: When you have sleep apnoea, you are breathing abnormally while you sleep. You may take pauses in breathing that can last a few seconds to a few minutes, or you may have periods of shallow breathing. Whenever your normal breathing gets interrupted, you move out of deep sleep and into light sleep. As a result, your sleep quality is poor, and you may wake up exhausted and feel tired throughout the day.
  • Diabetes: Glucose is an energy source for the cells in your body. When you have diabetes, the amount of glucose in your blood (blood sugar) is too high—and not enough glucose gets to your cells, which is where it’s needed. Diabetes can cause fatigue along with many other symptoms, such as feeling very thirsty or hungry and needing to urinate more often.
  • Heart failure: When your heart isn’t able to pump blood through your body normally, you may feel very tired. Even simple activities, such as walking or climbing the stairs, can leave you exhausted and out of breath. That’s because your muscles, arms, and legs aren’t getting a steady enough supply of blood. Other symptoms of heart failure include shortness of breath and swelling of the feet, ankles, legs, and belly.

Get Help

If you’ve been feeling fatigued for a few weeks, don’t ignore it. Don’t settle for always feeling rundown and having low-energy. Speak to your health care professional. Together, you can try to figure out what may be causing your fatigue and get the treatment you may need. If you are managing a health condition that causes fatigue, talk to your healthcare team about how to best boost energy levels.

Dipali Davé, MD, MHA, is a physician and the Assistant Editor and Medical Researcher for Pfizer’s Get Healthy Stay Healthy website.

[1] [2] [3]


  • 1. 2007 National Survey of Mental Health and Wellbeing: Summary of Results. Australian Bureau of Statistics 4326.0.
  • 2. 2016/7 New Zealand Health Survey. Ministry of Health NZ.
  • 3. Beyondblue.org.au.(2018). beyondblue. Accessed 14 Feb. 2018.
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