Feeling unusually tired, developing a rash or noticing aching joints does not automatically mean you have an autoimmune disease. These symptoms are common and can have many causes.
What matters more is the pattern. Symptoms that keep returning, last for weeks or affect several areas of the body deserve more attention than one symptom on its own.
Autoimmune diseases develop when the immune system mistakenly targets the body’s own cells or tissues. Many autoimmune conditions also involve inflammation, which can cause pain, heat, redness or swelling. Inflammation itself is not proof of autoimmune disease.
Different conditions affect different parts of the body. There is no single list of symptoms that applies to everyone. Speak to a healthcare professional when symptoms are new, unexplained or do not go away.
1. Persistent fatigue
Fatigue can occur with lupus, rheumatoid arthritis, Sjögren’s disease, coeliac disease and other autoimmune conditions. It may feel deeper than ordinary tiredness. Rest may not fully relieve it.
Fatigue is also common with poor sleep, iron deficiency, thyroid problems, infection and stress. Many other health problems can affect energy too. Pay more attention when fatigue lasts or appears with other new symptoms.
2. Joint pain, stiffness or swelling
Rheumatoid arthritis can cause painful, swollen or stiff joints. Morning stiffness may last longer than expected, and the small joints of the hands and feet are often affected. Lupus can also cause joint and muscle pain.
Joint pain has many other causes. Look for a pattern rather than one sore joint. Repeated swelling, warmth or long morning stiffness should be discussed with a healthcare professional.
3. Unexplained muscle aches or weakness
Muscle pain and muscle weakness are not the same. Pain means a muscle hurts. Weakness means tasks such as climbing stairs, standing from a chair or lifting something have become harder than usual.
Some autoimmune conditions, including myositis, can cause muscle weakness. Infection and medicines can do the same. Nutritional or nerve problems are other possible causes. A lasting change in strength should be assessed.
4. Brain fog or difficulty concentrating
“Brain fog” is not a diagnosis. People often use the term for poor concentration, forgetfulness, slow thinking or trouble finding words.
These symptoms can occur with some long-term or neurological conditions. Poor sleep, stress, low mood, medicines and nutritional problems can cause them too. A lasting change matters more when it appears with other symptoms.
5. Recurring skin changes or rashes
Several autoimmune conditions can affect the skin. Lupus may cause a rash, sometimes after sun exposure. Coeliac disease can cause an itchy blistering rash called dermatitis herpetiformis. Some forms of myositis can also cause a rash.
Most rashes are not autoimmune. Pay attention if a rash keeps returning or appears with joint pain, fatigue or other unexplained symptoms. Take a clear photo while it is visible. This can help your GP see the pattern.
6. Persistent digestive problems
Bloating, abdominal pain, diarrhoea and constipation are common. They have many possible causes. They can also occur with coeliac disease. In this condition, gluten triggers an immune response that harms the small intestine.
Do not start a gluten-free diet before coeliac testing unless a clinician advises you to. Removing gluten too early can make test results less reliable.
7. Numbness, tingling or sensory changes
Numbness or tingling can come from a trapped nerve or vitamin deficiency. Many other problems can cause it too. It can occur in multiple sclerosis. Coeliac disease can also sometimes be linked with nerve symptoms in the hands or feet.
Speak to your GP if these symptoms keep returning. This is more important if you also notice changes in vision, balance or muscle strength. Sudden neurological symptoms need urgent medical attention.
8. Persistent dry eyes or dry mouth
Dry eyes or a dry mouth can be caused by dehydration, medicines, contact lenses or the environment. These causes are common. When both problems last, they can also be a feature of Sjögren’s disease.
Sjögren’s can also cause fatigue and aching joints or muscles. Simple measures may help mild dryness. Speak to your GP if the problem lasts or keeps returning.
9. Unexplained hair loss
Stress, iron deficiency, hormonal changes and genetics are common causes of hair loss. Hair loss can also occur with autoimmune conditions such as lupus.
Thyroid problems may affect hair and energy too, and some thyroid disease is autoimmune. If this is relevant to you, our guide to autoimmune thyroiditis explains the condition in more detail.
Sudden, patchy or unexplained hair loss deserves assessment, especially if other symptoms are present.
10. Recurrent unexplained fever or swollen glands
Fever is most often caused by infection. Repeated fever or swollen glands can sometimes occur with inflammatory or autoimmune conditions, including lupus.
One short fever during an infection is common. Repeated episodes are different, especially when they appear with joint swelling, rash, fatigue or unexplained weight changes. Persistent or recurrent fever should be assessed.
The pattern matters more than one symptom
One symptom rarely tells the whole story. Fatigue, bloating, hair loss and aching joints are all common outside autoimmune disease.
A pattern becomes more useful when symptoms last, return in flares or affect several body systems. Family history can add context too. Some autoimmune conditions occur more often within families. This does not mean you will develop the same condition.
A short symptom diary can help. Note when symptoms began and how long they last. Record whether several symptoms appear together. Also note how they affect daily life. The aim is not to diagnose yourself. It is to give your clinician a clearer picture.
When should you speak to your GP?
Arrange an appointment if symptoms are new and unexplained or keep returning. Speak to your GP if they are getting worse or interfere with daily life. Also seek advice for visible joint swelling, persistent rashes, neurological changes, unexplained weight changes or recurrent fever.
There is no single blood test for every autoimmune disease. Tests should match the symptoms and the condition being considered. Your medical history and examination matter too. Test results need to be read in that wider context.
Looking at the wider picture
Medical diagnosis is one part of the picture for someone with an autoimmune condition or ongoing unexplained symptoms. Diet, digestion, sleep and stress can also affect day-to-day health. Lifestyle and nutritional status may matter too.
These factors should not be presented as the cause of every autoimmune disease. They can instead be reviewed to see where practical support may be useful.
How the London Clinic of Nutrition supports autoimmune health
At the London Clinic of Nutrition, practitioners use a personalised nutrition and functional medicine approach. Assessment may include your diagnosis, symptom history, diet, digestive health, medicines, supplements, sleep, stress and previous investigations.
Further testing is considered only when it may provide useful information. There is no standard test plan for everyone. Recommendations are also tailored to the individual rather than based on one autoimmune protocol.
Nutrition and functional medicine support are designed to work alongside appropriate medical diagnosis, monitoring and treatment.
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Frequently asked questions
Yes. Some autoimmune diseases have times when symptoms become worse and times when they improve. These may be called flares, relapses or remissions. The term used depends on the condition.
No. Fatigue has many possible causes. It matters more when it lasts or has no clear cause. It is also worth checking when it appears with joint swelling, rashes, digestive problems or nerve symptoms.
No. Tests should match the symptoms and the condition being considered. Some antibodies can also occur in people without autoimmune disease. This is why a test result needs to be read in context.
Nutrition can form part of wider supportive care. There is no single diet that suits every autoimmune condition. The best approach depends on the diagnosis, treatment, nutritional needs and the individual. Read more about diets for autoimmune disease management.
Yes. Some autoimmune diseases can start with mild or vague symptoms. Others may be found during tests for another problem. A lack of obvious symptoms does not rule a condition in or out. The full clinical picture still matters.
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