Causes and Risk Factors
The exact cause is unknown. Lupus appears to develop when a genetic predisposition meets environmental triggers such as sunlight, infections, and certain medications. Hormones likely play a role, which helps explain why about nine out of ten adults with lupus are women. Lupus is not contagious and is not caused by anything a patient did; flares, however, can be set off by sun exposure, infections, physical or emotional stress, and stopping medications abruptly.Symptoms
Lupus is famously variable — no two cases look quite alike — but common features include:- Joint pain and swelling: Aching, stiff joints resembling inflammatory arthritis, usually without the permanent joint damage of rheumatoid arthritis.
- Butterfly rash: A red rash across the cheeks and bridge of the nose, often after sun exposure.
- Photosensitivity: Sunlight can trigger both rashes and systemic flares — an everyday consideration under the strong Florida sun, where daily sunscreen and protective clothing are part of treatment.
- Fatigue and fever: Profound tiredness and low-grade fevers accompany active disease.
- Blood abnormalities: Lupus can cause anemia, low white cells, and thrombocytopenia (low platelets).
- Kidney involvement: Lupus nephritis may cause swelling, foamy urine, and high blood pressure, and is a major driver of long-term outcomes.
- Other features: Fingers that blanch in the cold (Raynaud phenomenon), mouth ulcers, hair thinning, and chest pain with deep breaths from inflammation of the heart or lung linings.
Diagnosis
No single test proves lupus. Physicians combine the clinical picture with blood tests — nearly everyone with lupus has a positive antinuclear antibody (ANA), and more specific antibodies such as anti-double-stranded DNA support the diagnosis — plus blood counts, kidney function tests, and urine studies to look for protein. Because early symptoms overlap with many other illnesses, diagnosis often takes time and repeated evaluation. Once lupus is diagnosed, many of the same tests are repeated periodically to track disease activity.Treatment
Treatment is tailored to which organs are involved and how active the disease is:- Hydroxychloroquine: Recommended for nearly all patients — it reduces flares, protects organs, and improves long-term survival.
- Corticosteroids: Prednisone controls flares quickly; the goal is always the lowest dose for the shortest time.
- Immunosuppressants: Methotrexate and similar medicines control joint and skin disease and allow lower steroid doses; stronger agents are used for kidney involvement.
- Sun protection and lifestyle: Broad-spectrum sunscreen, not smoking, regular exercise, and keeping vaccinations current all reduce complications.
- Regular monitoring: Periodic blood and urine testing catches kidney inflammation early, when it is most treatable.
Living With Lupus
Lupus treatment succeeds over decades, not visits, and most of what determines the outcome happens between appointments: daily hydroxychloroquine, sun that is managed rather than avoided, fevers that are reported, and kidneys and heart checked before they announce themselves.
Hydroxychloroquine is taken through remission
Hydroxychloroquine takes two to three months to work fully and is continued indefinitely, including when the disease is quiet, because stopping it roughly doubles the chance of a flare and forfeits its protection against clots, kidney damage, and cardiovascular events. The one meaningful risk is to the retina, which is checked with a baseline eye exam and then yearly after five years of use, sooner in people with kidney disease.
Steroids as a bridge, not a plan
Prednisone controls a flare quickly and is then tapered as fast as the disease allows, because bone loss, infection, diabetes, and cardiovascular damage accumulate with every month above a low dose. Needing repeated courses is the signal to add or increase a steroid-sparing agent: methotrexate for joints and skin, mycophenolate or azathioprine for kidney or blood involvement, and biologics such as belimumab or anifrolumab when those are not enough. A bisphosphonate such as alendronate is considered for longer courses, since osteoporosis is common in lupus.
Sun in Florida: manage it rather than hide from it
Ultraviolet light triggers rashes and whole-body flares, and here it is strong year-round. Daily broad-spectrum sunscreen rated SPF 30 or higher, reapplied outdoors, UV-blocking clothing and a wide hat, shade in the middle of the day, and window film for the car are the routine; our Florida sun safety guide covers the details. Some medications increase photosensitivity, including doxycycline and hydrochlorothiazide, and alternatives are chosen.
Infections, vaccines, heart, and kidneys
A fever on immunosuppressive treatment is reported the same day, because infection and flare look alike and are treated in opposite ways. Inactivated vaccines, including the recombinant shingles vaccine, flu, COVID-19, and pneumococcal vaccines, are recommended, while live vaccines are avoided on stronger immunosuppression; our adult vaccine checklist lists them. Lupus roughly doubles cardiovascular risk, so blood pressure and cholesterol are treated more aggressively than the numbers alone suggest and smoking is stopped. A urine protein check at every visit catches lupus nephritis before it causes chronic kidney disease.
Pregnancy, clotting, and what is not a flare
Pregnancy is planned after at least six months of quiet disease, with hydroxychloroquine continued and methotrexate stopped well in advance; antiphospholipid antibodies, covered on the antiphospholipid syndrome and lupus anticoagulant pages, change both contraception and pregnancy management. Widespread pain with fatigue and normal inflammatory markers is often coexisting fibromyalgia rather than active lupus, and is not treated with more steroids. Dry eyes and mouth suggest overlapping Sjögren's syndrome, and a lupus-like illness that began after hydralazine or certain other drugs usually resolves when it is stopped. Our immunology team coordinates monitoring with rheumatology. NIAMS and the American College of Rheumatology publish patient guidance on living with lupus.
If you have lupus and are not sure when your urine protein or eye exam was last checked, schedule a visit.