About 5% of people, across more than 80 related disorders. Thyroiditis, rheumatoid arthritis and type 1 diabetes are among the common ones. There is no cure yet, so treatment aims to ease symptoms and protect organs.

DMPA carries a small increase in venous thromboembolism risk. Known clotting mutations and being postpartum with other VTE risks are also on the list.

Check for dosing errors, interacting medicines and new kidney impairment. Methotrexate is cleared through the kidneys, so a change in renal function can alter its safety.

Pulmonary fibrosis and pulmonary hypertension. Systemic sclerosis can affect internal organs as well as skin, so respiratory involvement belongs in the assessment.

They suppress the underlying inflammation, helping prevent erosions and reduce pain. Benefits extend beyond joints: controlling inflammation can also reduce cardiovascular morbidity.

Immune-mediated damage to pancreatic cells disrupts blood glucose control. It is an example of autoimmunity directed at a particular organ rather than a multisystem connective tissue disease.

No. Diagnosis requires the clinical pattern, investigations and consideration of mimics. A steroid response should not be the defining diagnostic feature.

tTG-IgA with total IgA, or tTG-IgA with DGP-IgG. Testing must occur while gluten is being eaten, and positive serology requires further diagnostic assessment.

Enthesitis can cause heel or sole pain. Dactylitis produces swelling across a whole digit. Nail psoriasis may cause pits or separation of the nail from its bed.

Blood or protein in urine may signal renal involvement. In suspected SLE, a blood count, complement levels and targeted antibody tests can add useful information alongside the clinical assessment.

Predominant low-back pain and stiffness, spinal ankylosis, or associated psoriasis point towards spondyloarthritis. Ankylosing spondylitis and psoriatic arthritis can enter the differential.

No. The RACGP algorithm supports clinical diagnosis in a typical presentation and advises against routine imaging for diagnosis. Investigate when atypical features or red flags suggest another cause.

Reconsider the diagnosis. RACGP advises further assessment for atypical symptoms and red flags; laboratory tests can be considered if inflammatory or immune disease is suspected.

Explore function, goals, concerns, values and preferences; explain options and agree goals to review. The RACGP algorithm recommends an individualised plan, not a radiograph-led approach.

No. ANA levels do not reliably track disease activity. Repeat testing is generally unhelpful unless the clinical picture has changed substantially.

Addison's originates in the adrenal glands. Secondary adrenal insufficiency results from inadequate pituitary ACTH release. The symptoms may overlap, but the site of the problem differs.

Yes. Non-live vaccines can be administered safely, although the immune response may be weaker. Some vaccines need additional doses, so use an individual vaccination plan.

Assess hip internal rotation and flexion; limited range and pain with these movements are listed examination features. Interpret findings alongside the history and overall assessment.

Shoulder and hip girdle pain with marked stiffness can make rising or lifting the arms difficult. Muscle strength and muscle enzymes are usually normal; true proximal weakness suggests another explanation.

No. It means liver inflammation. Autoimmune hepatitis occurs when the immune system attacks the liver; medicines, alcohol and other non-infectious causes can also produce hepatitis.

Consider further tests for atypical symptoms or red flags. The RACGP algorithm notes imaging when an alternative diagnosis or serious pathology is suspected, and laboratory tests if inflammatory or immune disease is suspected.

The RACGP algorithm emphasises exercise and weight management, alongside education and an individualised plan that reflects the person's needs and preferences.

These antibodies, seen with Sjögren's and cutaneous lupus, are associated with congenital heart block in the fetus. Their relevance extends beyond diagnosing maternal disease.

Difficulty breathing. Myasthenia can weaken respiratory muscles, not just cause ptosis or limb weakness. Breathing difficulty requires an ambulance via triple zero.