What Are The Most Common Causes For Tiredness?

5 min read

Last Modified 3 March 2021 First Added 23 February 2017

By Gemma Curtis

Tiredness isn’t just caused by lack of sleep. You may feel tired more often than not, and this could be down to an underlying condition or a certain lifestyle choice. But what can you do to stop feeling tired? We investigate the most common causes for tiredness and how you can avoid them.

Medical conditions

There are lots of different illnesses that cause tiredness. They range in severity but most can be treated easily. The most common illness that causes tiredness, especially in women, is anaemia. This occurs when the body doesn’t have enough iron to produce red blood cells, causing a lack of oxygen in your organs. Symptoms of anaemia include tiredness and lethargy, heart palpitations and shortness of breath. It is most commonly caused by blood loss, but can also occur when there is a lack of iron in the diet. The NHS say, ‘Treatment for iron deficiency anaemia involves taking iron supplements to boost the low levels of iron in your body. This is usually effective, and the condition rarely causes long-term problems’. Eating foods rich in iron can also help, such as dark-green, leafy vegetables, pulses, beans and meat/fish.

Iron rich foods

Other illnesses that cause tiredness are chronic fatigue and under-active thyroid problems. Chronic fatigue (also called myalgic encephalomyelitis, or ME), is a debilitating tiredness that causes severe lethargy and leaves patients feeling run-down for months on end. There is no one cause of this illness, but it can be linked to hormone imbalance and issues with the immune system. It is best treated with medication and physiotherapy. It is clear to see that these illnesses have similar symptoms, so it’s really important to visit your GP if to find out the exact cause if you experience any of them.

Depression and anxiety

Depression is a neurological disorder, however it has some physical side effects. One of the most prominent symptoms of depression is lack of energy. People who suffer with depression often find it very hard to get a good sleep. A large contributing factor to depression is stress. Experts at ZME Science say ‘stress can exhaust the brain and lead to depression, which always seems to trigger more vicious cycle problems: you’re depressed so you become more stressful; you have trouble sleeping so you feel tired; you feel tired so you don’t feel like doing anything meaningful anymore’. This cycle of poor sleep fuelling tiredness means that, for some, depression can be extremely hard to beat.

Meditating couple

Fortunately, there are many ways in which we can treat depression. It’s extremely important to seek medical advice if you have depression, so they can prescribe medication if required. However, you can aid the process of recovery by following some non-drug remedies. Health.com suggest keeping a mood diary, visiting support groups and practicing meditation.

Related: How Important Is It To Keep A Journal By Your Bed?

Poor quality sleep

When it comes to sleep, it’s all about quality, not necessarily quantity. Poor quality sleep can lead to many health issues and, of course, tiredness. If you have bad sleep, you are more likely to have impaired brain function, weight gain and increased risk of diseases. Authority Nutrition report ‘Sleeping less than 7-8 hours per night is linked to an increased risk of heart disease and stroke’. They also said ‘Sleep deprivation can cause pre-diabetes in healthy adults, in as little as 6 days. Many studies show a strong link between short sleep duration and type 2 diabetes risk’. It shows just how important it is to get a good night’s sleep. But how can we ensure that we get a high quality sleep every night?

Woman tired on bed

Read more: What Is Insomnia & Can You Cure It?


The key to improving your sleep, and therefore your time awake, is by improving your lifestyle. There are certain factors which play a vital role in good sleep. You can easily improve your lifestyle by stopping these bad habits:

  • Dehydration– Not drinking enough fluids can make you feel sluggish and give you headaches. Dr Roger Henderson told the Natural Dehydration Council, ‘Many of my patients do not drink enough fluid each day and only believe they are dehydrated when they start to feel thirsty. Yet other symptoms of dehydration appear before this, including fatigue and tiredness, headaches and poor concentration’. You should drink at least 6-8 glasses of water a day.
  • Disturbed sleep– Shift work and being woken up regularly can affect your mood. The NHS say ‘If you have a disturbed sleep pattern – for instance, if you work night shifts, sleep in the day or look after young children – it can be difficult to get a good night’s sleep, and you’ll feel tired during the day’.
  • Poor diet– Sugary foods, caffeine and junk food all have a negative effect on your body. It’s also important not to skip breakfast or drink alcohol before bed.
  • Bad sleep hygiene– Not having a regular night-time routine, using phones in bed and using your bedroom for anything other than sleeping or relaxing can ruin your sleep. Try resetting your sleep hygiene.

Drinking water

How do you combat tiredness? Have your say in the comments!

About the author