Many people suffer from persistent physical complaints, such as dizziness or pain, that don't appear to have an obvious medical cause.
They are sometimes termed "medically unexplained symptoms" or "functional" symptoms when they last for more than a few weeks, but doctors can't find any disease or problem with the body that may be the cause.
This doesn't mean that the symptoms are faked or "all in the head" – they are real and can affect your ability to function properly. Not understanding the cause can make them even more distressing and difficult to cope with.
Medically unexplained symptoms are surprisingly common, accounting for up to a fifth of all GP consultations in the UK.
Why do they happen?
Many people suffering from medically unexplained symptoms such as exhaustion (fatigue), pain and heart palpitations also have depression or anxiety disorders. Treating an associated psychological problem can often relieve the physical symptoms.
For others, the symptoms may be part of a poorly understood syndrome, such as:
chronic fatigue syndrome (CFS) – also known as ME, which causes persistent fatigue
irritable bowel syndrome (IBS) – a common condition affecting the digestive system, which can cause stomach cramps, bloating, diarrhoea and/or constipation
fibromyalgia – which causes pain all over the body
A psychological or life problem may play a role in these syndromes as well – for example, IBS symptoms can be brought on by stress in some people, and managing the stress can help to relieve the symptoms. However, there may be other triggers (for example, IBS and CFS can occur after infections).
Sometimes, there is simply no explanation and doctors can't diagnose a cause. This isn't unusual in medicine and doesn't mean that nothing can be done to help you (see "How can my GP help?" below).
If you're worried that you have an underlying disease that has been missed by your doctor, you can ask for a second opinion.
What sort of complaints can be 'unexplained'?
Medically unexplained symptoms tend to be quite general problems, such as:
shortness of breath
dizziness and feeling sick
These are often experienced alongside depression and/or anxiety (see "What's the connection between mental and physical health?" below).
The symptoms vary in how much they affect people – some will see their GP with relatively minor symptoms, while others may become disabled by them.
Who is more likely to have them?
Unexplained symptoms are reported to be more common among:
those who have recently had an infection or physical illness, or those affected by the ill health or death of a relative
those who have previously experienced problems such as depression and anxiety
Women are more likely than men to see their GP with symptoms, and some older people don't like to bother their GP.
What's the connection between physical and mental health?
Just as poor physical health can lead to unhappiness and psychological problems, the opposite is also true.
Conditions such as low back pain and IBS are known to be triggered or made worse by psychological problems such as stress, anxiety or depression.
This can lead to a vicious circle – for example, the emotional upset from being in constant physical pain can lead to depression, the depression then worsens the pain, and may trigger other symptoms.
How can my GP help?
Your GP will aim to rule out all the possible serious causes of your symptoms. You'll probably have a thorough physical examination and blood tests.
It's important to consider whether the cause of your symptoms may be any medication you are taking.
Your GP should also investigate whether you might have an associated problem, such as depression or anxiety, that may be causing or worsening your symptoms.
You should tell them:
what the symptoms are like, when they started and what makes them better or worse
what you think or fear is the cause of your symptoms and your expectations of tests and treatments
how the symptoms affect what you can do
how upsetting the symptoms are
There are then a number of things you can do that may help.
You and your GP may need to draw up a personal health plan – this means agreeing some lifestyle changes and goals that you both think will help your symptoms.
You may be referred for a talking therapy such as cognitive behavioural therapy (CBT). CBT aims to help you manage your symptoms by enabling you to understand links between your symptoms, worries, feelings and behaviour.
Medication such as antidepressants can be helpful, even if you're not depressed. However, drugs aren't always the answer – painkillers or sedatives, for example, may lead to dependence. The possible benefits of medication always need to be weighed against the potential side effects.
If you feel your GP isn't taking your complaint seriously, you can get a second opinion.
What can I do myself to improve my symptoms?
There are things you can do yourself that can improve or even relieve some physical symptoms, such as regular exercise and stress management.
Regular exercise – say, three 20-minute sessions a week – will at least keep you fit and give you a chance to take a break from other tasks, or just to get out of the house. Many people find that it also boosts their mood. The exact amount of exercise or activity needs to match your current health and capabilities.
Managing stress is very important, as this has been linked to problems such as pain and IBS. Learn some relaxation tips to relieve stress.
Generally, it should help to plan some pleasurable personal time to unwind – whatever helps you relax, whether it's yoga classes, meditation or walks in the countryside.
Your body has a remarkable ability to recover and there's a good chance that your symptoms will get better in time, even without any specific treatment.