We all feel tired occasionally — a poor night’s sleep, a long day at work, or burning the candle at both ends can leave anyone flagging. But what if you’re feeling exhausted day after day, no matter how much rest you get?
Constant tiredness, also known as fatigue, is one of the most common reasons people see their GP. It can affect your concentration, mood, and ability to get through the day — and sometimes it’s a sign that something else is going on beneath the surface.
In this article, we’ll explore some of the most common causes of fatigue, when to be concerned, and how to start feeling more energised. If you’re struggling to find answers, remember you can always talk to a doctor online to discuss your symptoms and get professional advice.
Table of Contents
What Is Fatigue?
Fatigue is more than just feeling sleepy — it’s a persistent sense of physical or mental exhaustion that doesn’t go away with rest. It can be a symptom of many different conditions, or sometimes result from lifestyle factors like poor sleep, diet, or stress.
Fatigue can come on gradually or suddenly and may affect your ability to focus, your motivation, and even your emotional resilience.
Common Causes of Fatigue
Fatigue has a wide range of possible causes, from the simple to the more serious. Here are some of the most common:
1. Poor Sleep Quality
Even if you’re getting enough hours in bed, you might not be sleeping well. Interrupted sleep, sleep apnoea, or insomnia can all leave you feeling unrefreshed in the morning. Screens before bedtime, caffeine late in the day, and irregular sleep schedules can also interfere with your natural sleep rhythm.
2. Stress, Anxiety or Depression
Mental health has a huge impact on your energy levels. Stress and anxiety can cause racing thoughts and restless nights, while depression can make it hard to get out of bed or feel motivated, even after sleeping well.
Fatigue is often one of the first noticeable signs of a mental health condition, so it’s important not to dismiss it.
3. Nutritional Deficiencies
Low levels of iron, vitamin D, vitamin B12 or folate can all lead to feelings of tiredness and weakness. Iron deficiency anaemia, in particular, is a common cause of fatigue — especially among women of childbearing age.
A simple blood test can check for these deficiencies, and treatment may include supplements or dietary changes.
4. Thyroid Problems
The thyroid is a small gland in your neck that regulates energy levels and metabolism. An underactive thyroid (hypothyroidism) can cause fatigue, weight gain, cold intolerance, and low mood. It’s more common in women and tends to develop slowly over time.
If your tiredness is accompanied by other subtle changes, it might be worth checking your thyroid function.
5. Chronic Fatigue Syndrome (CFS/ME)
CFS, or myalgic encephalomyelitis (ME), is a more complex condition where extreme fatigue lasts for six months or more and doesn’t improve with rest. It often includes other symptoms like brain fog, muscle pain, and sleep disturbances.
There is no single test for CFS/ME, and diagnosis involves ruling out other potential causes first.
6. Infections or Illness
Ongoing fatigue can also follow a viral or bacterial infection — such as glandular fever, COVID-19, or flu — even after the main symptoms have passed. This kind of post-viral fatigue can linger for weeks or even months.
Fatigue may also signal other underlying health problems, including diabetes, heart disease, or liver disorders.
What Can You Do About It?
Feeling constantly tired can be incredibly frustrating, but there are steps you can take to manage your energy and uncover the root cause.
1. Review Your Sleep Routine
Aim for 7–9 hours of sleep per night, and try to keep a consistent sleep and wake time — even on weekends. Avoid screens at least an hour before bed, cut back on caffeine after midday, and create a calm sleep environment.
2. Take Care of Your Mental Health
If stress or low mood is dragging you down, don’t try to cope alone. Therapies like CBT, relaxation techniques, and even a chat with someone you trust can make a big difference. If things feel overwhelming, it might be time to talk to a doctor online about how you’re feeling.
3. Eat Well and Stay Hydrated
A balanced diet with whole foods, plenty of vegetables, and enough protein can fuel your body properly. Avoid excessive sugar and processed foods that lead to energy crashes, and aim to drink 6–8 glasses of water a day.
4. Get Some Gentle Exercise
Ironically, regular light exercise — like walking, stretching, or swimming — can help fight fatigue. It boosts circulation, lifts your mood, and improves sleep quality.
5. Speak to a GP
If your fatigue has lasted longer than a few weeks, or is starting to interfere with daily life, don’t ignore it. A GP can help identify the cause and recommend the right investigations or treatments. You can easily talk to a doctor online if you prefer a convenient and discreet way to get checked out.
Final Thoughts
Ongoing fatigue isn’t something you should just put up with. Whether it’s due to lifestyle, emotional health, or an underlying medical issue, feeling tired all the time deserves attention and support.
If you’re unsure where to begin or don’t have the time to wait for a face-to-face appointment, talk to a doctor online through tapGP. A quick conversation could be the first step toward feeling like yourself again.
