Can Rheumatic Diseases Cause Fatigue?

Fatigue is more than feeling tired after a busy day. It can feel like a persistent lack of physical or mental energy that affects work, exercise and everyday activities.

Rheumatic diseases can contribute to fatigue, sometimes even when joint pain is mild. But fatigue has many possible causes. On its own, it does not mean that someone has an autoimmune disease or that a known rheumatic disease is flaring.

How can a rheumatic disease cause fatigue?

In inflammatory diseases such as rheumatoid arthritis, lupus, psoriatic arthritis, axial spondyloarthritis and Sjögren’s disease, inflammation can contribute to fatigue. Fatigue may worsen during a flare, but it can also continue when disease activity is low or in remission.¹

Other effects of the disease can add to it:

• Pain or stiffness may interrupt sleep and make daily activities harder.
• Inflammation can contribute to anemia.
• Some medicines can cause tiredness or affect sleep.
• Reduced activity during a difficult period may lead to deconditioning.
• Stress, low mood and the demands of living with a long-term condition can also play a part.

Fatigue is not exclusive to autoimmune disease. Fibromyalgia, for example, is a chronic pain condition often managed in rheumatology, and fatigue can be one of its symptoms. Its presence does not mean there is active inflammation.

Fatigue with joint pain: could it be autoimmune?

It is understandable to wonder whether fatigue and joint pain are connected. Inflammatory arthritis can cause both, but these symptoms can also occur for many other reasons.

Fatigue may be an early or prominent symptom of some rheumatic diseases. However, fatigue alone is not enough to diagnose rheumatoid arthritis, lupus or another autoimmune condition. A clinician considers the full history, examination and, when appropriate, test results.

Could a vitamin or mineral deficiency be contributing?

Yes. Some deficiencies can cause fatigue, particularly when they lead to anemia or affect muscle and nerve function.

• Iron deficiency: Iron-deficiency anemia can cause fatigue, weakness and shortness of breath. A clinician may consider iron studies as well as a blood count, depending on the person’s symptoms and history.²
• Vitamin B12 or folate deficiency: Either can cause anemia and tiredness. B12 deficiency may also cause tingling, numbness or balance problems, sometimes before anemia is recognized.³,⁴
• Vitamin D deficiency: Significant deficiency can cause bone pain and muscle weakness, which may affect energy and function. Fatigue is nonspecific, and vitamin D supplements are not a guaranteed treatment for it.⁵

Other nutrient or mineral deficiencies may be relevant in particular circumstances, but fatigue alone cannot identify which one is present. Taking supplements without evidence of a deficiency may not help and can sometimes cause harm.

Fatigue can have causes outside rheumatology

A clinician may also consider sleep problems, thyroid disease, diabetes, infection, kidney or liver problems, medication effects, anxiety or depression. More than one factor can be present at the same time. Persistent fatigue deserves an assessment that looks at the whole picture rather than focusing on a single test or diagnosis.⁶

How is the cause assessed?

The assessment usually starts with questions about when the fatigue began, how it affects daily life, sleep, medications and other symptoms. The clinician may ask about joint swelling or prolonged morning stiffness, muscle weakness, fever, weight changes, breathlessness, numbness or changes in mood.

A physical examination and tests may be appropriate. Depending on the findings, these could include a blood count, iron studies, thyroid or glucose testing, vitamin levels, or inflammation tests such as ESR and CRP. There is no single test that explains fatigue in everyone, and not every person needs the same investigations.

If you already have a rheumatic condition, new or worsening fatigue may prompt a review of disease activity and other possible contributors. Fatigue alone, however, is not enough to determine whether treatment should change. The 2023 EULAR recommendations support an individualized approach that may include tailored physical activity and education or psychological support. Adjusting disease-modifying treatment may be considered when clinically indicated.¹

Frequently asked questions

Can fatigue be the only symptom of lupus or rheumatoid arthritis?

Fatigue can be an early or prominent symptom, but it is common in many conditions and does not by itself establish a diagnosis. A clinician looks for other symptoms and signs and decides whether further assessment is needed.

Should I take vitamin D or B12 supplements for fatigue?

Supplements are most useful when a deficiency is confirmed or there is another clinical reason to take them. Ask a healthcare professional whether testing or supplementation is appropriate for you.

Why am I still tired when my rheumatic disease is in remission?

Fatigue can persist even when inflammation is well controlled. Pain, poor sleep, anemia, medication effects, other health conditions, low mood and reduced activity may contribute.

Which tests might be done for fatigue?

Tests depend on your symptoms and medical history. They may include a blood count, iron studies, thyroid or glucose tests, vitamin levels, or ESR and CRP if inflammation is suspected. Not everyone needs every test.

When is fatigue an emergency?

Fatigue that develops gradually is not usually an emergency by itself. Seek urgent medical care if it occurs with chest pain, severe difficulty breathing, fainting, confusion or another sudden, severe symptom.

The key point

Rheumatic inflammation can contribute to fatigue, but so can pain, poor sleep, anemia, nutrient deficiencies, medication effects and many other health conditions. A careful assessment can help identify treatable contributors and guide the next steps. Treatment should address the cause or combination of causes rather than assume that fatigue is due to rheumatic disease or a vitamin deficiency.