context: Rheumatoid arthritis ( RA) and lupus are autoimmune diseases. They result from your immune system mistakenly attacking your own body. With RA, your immune system mainly goes after your joints. That's also the case for about 2 out of every 3 of people who have lupus. But lupus, the symptoms of which can vary widely from person to person, can affect many other parts of the body as well. Both conditions affect your joints, so it's easy to confuse them. In fact, lupus has been called "the great imitator" because it can seem a lot like not just RA but many other diseases, too. So it's important to know how RA and lupus do and do not resemble each other. Then you and your doctor can get the right diagnosis and treatments. Both conditions are much more common in women, who are 2-3 times more likely than men to have RA. And women also are up to 9 times more likely to get lupus. RA commonly affects the smaller joints of the fingers, hands, and feet. It also can flare in your wrists, elbows, and other body parts. You might notice symptoms in different joints at different times. But they're usually symmetric. That means if the joints in your right hand hurt or feel stiff, you'll notice it in your left hand, too. RA symptoms sometimes come on so slowly that you can't tell anything is wrong. Most people have periods when their problems get worse. They're called flares. When symptoms are quiet, it's called remission. Some of the classic signs and symptoms are: Pain, swelling, and tenderness, usually in more than one joint Joint stiffness, which makes it hard to move, especially first thing in the morning Deformed joints, although this usually happens much later in the disease Rheumatoid arthritis can affect other parts of your body, too. It can cause: Dry eyes and dry mouth Rheumatoid nodules or lumps under your skin near the joints that usually don't hurt Shortness of breath and chest pain Tiredness, which sometimes, but not always, happens if you don't have enough red blood cells, a problem called anemia Weight loss Numbness and tingling in your hands Lupus can appear slowly or suddenly. It can be mild or severe. It, too, often switches between flare-ups and remissions. When lupus affects the joints, the symptoms can mimic those for RA: pain, stiffness, and swelling. Typically, they're not as bad with lupus. You also may have other symptoms that are common with RA, such as a mild fever, weight loss, and dry eyes. Lupus can trigger some distinct symptoms of its own. They include a "butterfly" rash (called a Malar rash) that stretches over your cheeks and nose, headaches, and kidney problems. No one test can tell if you have RA or lupus. Instead, your doctor will ask about your symptoms and family history, do a physical exam, and order some lab and imaging tests. During the physical exam, your doctor will feel your joints to see if the swelling feels hard. If it does, it could mean you have osteoarthritis. Swelling caused by RA tends to be softer. If tests show you have an antibody called anticyclic citrullinated peptide, you very likely have RA. If another test detects an immune system protein called rheumatoid factor ( RF), there's an 80% chance you could have RA or another inflammatory disease. X-rays, ultrasounds, and other imaging tests can detect damage to your joints, but usually only when you've had RA for a while. Lupus is harder to diagnose than RA. Sometimes it can take years to confirm you have lupus. Your doctor will give you a physical exam and order blood and imaging tests. She also will be looking for 11 specific symptoms of the condition. If you have 4 or more of these symptoms, you may have lupus: Butterfly-shaped rash across cheeks and nose Raised red patches on skin Skin rash from sunlight Ulcers, or open sores, in the mouth or nose that are usually painless Arthritis in at least two joints plus tenderness or swelling Inflamed lining around the heart or the lungs or both Seizures or psychosis, such as delusions or hallucinations, or both Kidney problems, such as too much protein in the urine Blood disorders, including low white cell or platelet counts Immune disorder Positive test for antinuclear antibodies There are no cures for RA or lupus. But many drugs can treat one or both conditions. For RA, most doctors will start with milder drugs that can relieve symptoms. These can be both prescription meds or over-the-counter nonsteroidal anti-inflammatory drugs ( NSAIDs) such as ibuprofen ( Advil, Motrin) and naproxen ( Aleve). Other drugs can slow RA's progress: Corticosteroids, which help control inflammation. DMARDs, which stands for disease modifying anti-rheumatic drugs, like methotrexate ( Trexall) and sulfasalazine ( Azulfidine). They make your immune system weaker, which can stop it from attacking your joints. Biologic drugs that target more specific parts of the immune system. Examples include adalimumab ( Humira) and etanercept ( Enbrel). Newer biologics called JAK inhibitors target a different part of the immune system than Humira and Enbrel. Tofacitinib ( Xeljanz) belongs in this group. Mild exercise like walking or yoga can help when your symptoms aren't bad. Rest is better when you're in the middle of a flare. If you've had a lot of joint damage, your doctor may suggest surgery to replace a joint or to fuse joints together. Lupus treatments can vary from person to person as much as its symptoms do. Many RA drugs also can treat lupus. NSAIDs may be the first thing you try if your joints are the main problem. Eventually, you will probably use several different therapies at the same time. Approved drugs for lupus include corticosteroids. These are powerful drugs and you should take the lowest dose needed for your symptoms. Your doctor likely will prescribe hydroxychloroquine ( Plaquenil), an antimalarial drug. Other options are chloroquine, which also is normally used to treat malaria, and belimumab ( Benlysta), a biologic drug which affects the immune system. You doctor may also want you to try drugs used for RA, such as DMARDs like methotrexate. With lupus, it's important to balance rest and exercise, and to get regular check-ups.