What is tiredness? Symptoms, causes and prevention

Tiredness refers to an overall feeling of fatigue and lack of energy. It can make a person feel exhausted physically, mentally, or both. It should not be confused with drowsiness or sleepiness, although they can be symptoms of tiredness. We all experience tiredness at some point in our lives, and there is typically a known reason for it (such as a long week at work or a late night out). Tiredness typically resolves after some rest and recuperation. However, persistent tiredness can be a sign of an underlying medical problem. This guide will explore tiredness, highlighting the causes, symptoms, and prevention/treatments available.

What is tiredness?

Tiredness, also referred to as ‘fatigue’, causes a lack of energy and motivation. It is commonly caused by external factors such as busy periods of time, physical strain, and disturbances affecting our normal sleeping pattern. Tiredness can be physical and/or mental and is typically no cause for concern. However, persistent tiredness may need to be investigated as it can be caused by an underlying health issue.

What are the symptoms of tiredness?

Tiredness can cause a variety of physical, mental and emotional symptoms, including:

  • Persistent fatigue
  • Sleepiness
  • Headaches
  • Dizziness
  • Muscle aches/weakness
  • Slowed reflexes
  • Decreased motivation
  • Impaired judgement
  • Irritability
  • Loss of appetite
  • Weakened immune system
  • blurred vision
  • Short-term memory problems
  • Difficulties concentrating
  • Hallucinations

What are the causes of tiredness?

Tiredness can be caused by a number of factors including lifestyle, medical problems and mental health issues.


Your lifestyle choices and activities can affect your energy levels and contribute to tiredness, particularly if you lead a busy life and adopt certain unhealthy habits. The following factors may contribute to your tiredness:

  • Physical exertion
  • Being overweight or obese
  • Lack of physical activity
  • Lack of sleep
  • Unhealthy diet
  • Emotional stress
  • Excessive alcohol consumption
  • Recreational drug use
  • Boredom

Medical problems

Certain medical conditions can also affect your body and contribute to your tiredness. These can include:

  • Anaemia – Iron anaemia is one of the most common medical reasons causing persistent tiredness.
  • Sleep apnoea – this causes your throat to narrows and close while you sleep, which interrupts your breathing and causes disrupted sleep patterns.
  • Hypothyroidism (underactive thyroid) – the lack of thyroxine can result in making you feel tired.
  • Coeliac disease – tiredness is a common symptom of coeliac disease.
  • Chronic fatigue syndrome (myalgic encephalomyelitis) – this condition causes episodes of tiredness that can last for months.
  • Diabetes – one of the main symptoms of diabetes is extreme tiredness.
  • Restless leg syndrome – this overwhelming urge to move your legs can lead to disrupted sleep and tiredness.

Mental health issues

Mental health issues can also contribute to tiredness, as chronic fatigue is a common symptom of depression, anxiety and seasonal affective disorder (SAD). This is because such conditions can affect your sleep pattern as well as cause an overall lack of energy and motivation. The mental strain that such conditions cause is typically the root cause of tiredness.

How to prevent and treat tiredness


You can help reduce tiredness caused by non-medical factors by adopting the following healthy habits:

  • Drink plenty of water to stay hydrated
  • Exercise regularly
  • Maintain a healthy BMI
  • Eat a healthy, balanced diet
  • Keep a regular sleeping pattern
  • Decrease your alcohol consumption
  • Stop smoking
  • Avoid known stressors
  • Keep a balanced work-life schedule
  • Do not use recreational drugs
  • Practice mindfulness, meditation and yoga


If the lifestyle changes mentioned above aren’t enough to lessen your tiredness, you may need to see your GP to establish whether there is an underlying health condition behind your lack of energy. This is important as tiredness can affect our professional and personal lives by affecting us on a physical, mental and emotional level.

Your GP will be able to diagnose the reason behind your chronic tiredness and recommend the correct course of treatment depending on the underlying cause.

How can I get tested for tiredness?

At a clinic

You can book a health check with one of our Certified Healthcare professionals at one of over 2,000 mobile clinics nationwide. We have two packages that are tiredness:

  • Essential Energy & Fatigue Plus: includes advanced vitamin deficiency checks, bone and muscle health, a full blood count, and an advanced thyroid function check to help assess the impact your lifestyle and diet is having on your energy levels.
  • Nutritional Therapy Plan: focuses on a “Eat Yourself Healthy” approach tailored to your health check results. This is our most comprehensive plan, which we recommend if you are struggling with weight management, Irritable Bowel Syndrome, low mood and anxiety, fertility problems and/or chronic fatigue.