What Is Lupus? Symptoms and Causes

Lupus is an autoimmune disease, meaning that the body’s immune system attacks healthy tissues by mistake. This leads to chronic (long-term) inflammation that damages the skin, kidneys, joints, and other organs. There are four main types of lupus that affect infants, children, and adults. Having lupus increases your risk of developing other health complications as well.1 Understanding what lupus is, how it’s caused, and what to expect can help you learn how to manage the disease.

The Immune System and Lupus

Lupus is an autoimmune disease, meaning that the body’s immune system accidentally recognizes healthy tissues as foreign invaders. The immune system’s main job is to protect the body from bacteria, viruses, and parasites that find their way in. These invaders express proteins known as antigens, which are recognized by the immune cells as foreign. This sets off alarms throughout the body that there is an infection, which creates inflammation. This inflammation helps recruit other immune cells to the infected area and triggers the healing process.2

In lupus, the immune system thinks the antigens found on certain organs are actually from invaders, triggering further inflammation. While short-term inflammation is helpful in clearing out invaders, long-term inflammation from lupus can be damaging to the skin, joints, kidneys, and other organs.

Who Develops Lupus?

Anyone can develop lupus, but women are much more likely to than men. According to the Centers for Disease Control and Prevention (CDC), women account for nine out of 10 lupus cases. Women are more likely to develop lupus during their child-bearing years—between the ages of 15 and 44. Men may still develop lupus, but it tends to be much less common.1

Women of color, particularly African American women, are two to three times more likely to develop lupus than White women. It’s also more common in Asian, Hispanic, and Native American women. Hispanic and African American women are more likely to develop a more severe form of lupus.1,3

What Causes Lupus?

Researchers aren’t quite sure what causes lupus. Lupus is not contagious, so you cannot catch it from another person. Instead, they believe it may be due to a combination of factors, including genetics, hormones, environment, and immune system problems.

If a family member has lupus, you’re more likely to develop it yourself. However, having one or more genes associated with lupus doesn’t necessarily mean you’ll develop it in your lifetime. If you do have these genes and are exposed to a trigger such as sunlight, certain medications, stress, or smoking, it may cause lupus to occur.1

Types of Lupus

There are four distinct types of lupus, and each affects certain organs and displays different symptoms. These include systemic lupus erythematosus, cutaneous lupus erythematosus, drug-induced lupus, and neonatal lupus.

Systemic Lupus Erythematosus (SLE)

According to the CDC, systemic lupus erythematosus (SLE) is the most common type of lupus. In SLE, the immune system attacks the body’s connective tissues such as the lining of blood vessels and cartilage.4 Other affected organs include the:

  • Joints
  • Kidneys
  • Skin
  • Central nervous system
  • Lungs

It’s estimated that between 322,000 to 1.5 million people are living with SLE in the United States. Most cases develop in women between the ages of 15 to 44, but around 20 percent of cases develop in people ages 50 and older.4

Cutaneous Lupus Erythematosus (CLE)

Cutaneous lupus erythematosus (CLE) is a type of lupus that affects the skin in people with or without SLE. There are two main groups of CLE — discoid lupus erythematosus (DLE) and subacute CLE.1

Localized DLE is characterized by a red, raised rash on the scalp or face known as a discoid rash. Over time, it can change colors to a darker brown or become scaly. Scarring and mouth and nose sores are also common in people with DLE. Generalized DLE affects other areas of the body, including the hands and arms. If you do not have SLE but develop DLE, there is a 5 to 10 percent chance you’ll develop SLE later in life. DLE tends to affect women in their 40s to 50s.5

Subacute CLE is more common in younger to middle-aged women. It is caused by exposure to the sun, which triggers the formation of scaly red rashes or lesions on the upper back, forearms, and arms. These may be mistaken for eczema or psoriasis. Around half of people with subacute CLE also have SLE, but they tend to have mild symptoms.5

Drug-Induced Lupus

Drug-induced lupus (erythematosus) is similar to SLE, but is instead caused by a reaction to certain types of medication. Typically, symptoms begin to show after taking medication for three to six months. Medications that cause drug-induced lupus are usually taken to treat other health conditions, such as rheumatoid arthritis (RA) or cardiovascular problems. These include:6

  • Tumor necrosis factor (TNF) alpha blockers for RA, such as infliximab, adalimumab, and etanercept
  • Cardiovascular drugs, such as hydralazine, quinidine, and procainamide
  • Cancer immunotherapy drugs, such as pembrolizumab
  • Antibiotics, such as minocycline

Symptoms of drug-induced lupus tend to be less severe than SLE, and the condition rarely affects any major organs. It tends to go away on its own after you stop taking the medication.6

Neonatal Lupus

Neonatal lupus is a rare form of lupus that occurs in newborn infants born to mothers with lupus or another autoimmune disease, such as RA or Sjogren’s syndrome.7 In some cases, the mother may not have any autoimmune disease, but she has the autoantibodies responsible for causing symptoms. These include the anti-Ro/SSA and anti-La/SSB antibodies, which are mainly found in women with SLE and Sjogren’s syndrome.8

When these antibodies are passed from mother to infant across the placenta, they can begin attacking the baby’s healthy issues. This causes a red rash that looks similar to SLE. It’s important to note that neonatal lupus is not a form of SLE, and symptoms typically clear up after several months with no lasting side effects. In rare cases, neonatal lupus can cause a congenital heart defect.7

Symptoms of Lupus

Lupus symptoms often vary from person to person and can depend on which type you have. They can affect almost any tissue or organ in the body. It’s common for lupus symptoms to come and go over time, and they may change as you get older. When symptoms are actively occurring, it’s known as a flare. After your symptoms resolve, you’re in remission and you should start to feel better.9

You may notice some symptoms getting worse before a lupus flare, such as:10

  • Rashes
  • Generalized pain
  • Fever
  • Dizziness
  • Severe headache
  • Feeling more fatigued than normal
  • Stomachache

Flares can be brought on by stressful events, such as infection, injury, overwork, or spending too much time in the sun. Even if you take medications to manage your lupus, flares can still be triggered.10 Knowing your triggers can help you avoid lupus flares or prepare for one before it happens.

Symptoms of SLE

Symptoms of SLE can range from mild to severe. At first, you may notice feeling extremely tired or fatigued, along with a vague feeling of illness or discomfort, known as malaise. Other symptoms that may develop include:4,9

  • Red, flat rash across the nose and cheeks, known as a butterfly rash
  • Worsening of skin rashes in sunlight
  • Joint pain that occurs in the same joints on both sides of the body
  • Muscle weakness and pain
  • Loss of appetite leading to weight loss
  • Fever higher than 100°F
  • Formation of calcium deposits under the skin, known as calcinosis
  • Development of tiny red spots on the skin, known as petechiae
  • Damaged blood vessels in the skin, known as vasculitis
  • Open sores or ulcers on the lining of the nose, mouth, or genitals
  • Hair loss, known as alopecia
  • Chest pain caused by inflammation in the lungs

Symptoms of Drug-Induced Lupus

Symptoms of drug-induced lupus are similar to SLE, which include:6

  • Malaise
  • Fever
  • Joint stiffness, pain, and swelling
  • Chest pain from inflammation in the lungs
  • Loss of appetite
  • Skin rashes, especially when the skin is exposed to sunlight

Symptoms can also be specific to the type of drug causing lupus. Specific symptoms of hydralazine-induced lupus include:11

  • Enlargement of the spleen and liver
  • Inflammation of the inner linings of the lungs, known as the pleura
  • Swelling of the lymph nodes

Specific symptoms of anti-TNF medications used to treat other autoimmune diseases include:11

  • Low platelet count, known as thrombocytopenia
  • Low white blood cell counts, known as leukopenia
  • Low red blood cell counts, known as anemia

Symptoms of Neonatal Lupus

The symptoms of neonatal lupus often look similar to SLE, but they are not the same condition. SLE is a life-long condition once it develops, while neonatal lupus symptoms typically go away within the first several months of an infant’s life. The most obvious sign is the red facial rash, which can develop in a butterfly- or raccoon-like pattern around the eyes. Skin rashes may also be seen on the arms, legs, and trunk of the body. These rashes can be sensitive to sunlight, which may trigger them or make them worse.7

Other symptoms associated with neonatal lupus include:7

  • Yellowing of the skin and eyes, known as jaundice
  • Low platelet counts
  • Low red blood cell counts
  • Low white blood cell counts
  • Enlarged spleen and liver
  • Inflammation in the liver, known as hepatitis

How Is Lupus Diagnosed?

Diagnosing lupus is not a straightforward process, and many people are diagnosed with another condition before being diagnosed with lupus. According to a survey conducted by the Lupus Foundation of America, 40 percent of people reported that their doctor told them they have another condition, and 23 percent were told their problems were psychological and not physical.12 Unfortunately, there is no one test that can confirm a lupus diagnosis. Your doctor will use a combination of your medical history, examinations, and blood work to make a diagnosis.13

Medical History and Physical Exam

Your doctor will first start by taking your medical history and performing a physical exam. Be sure to tell them if you have any family history of lupus or any other autoimmune diseases, as this can help point them to a diagnosis more quickly. If you start to have flares, try writing down when they happen, what symptoms you’re having, and when they start to get better. During the physical exam, your doctor will look at your skin for rashes and any other signs of illness. If your rashes get worse in the sunlight, be sure to let them know.13

Blood Work

If your doctor believes you may have lupus, they will order blood work to help guide their diagnosis. You’ll likely have a complete blood count (CBC) to look at the levels of red and white blood cells and platelets. Another test commonly used to diagnose autoimmune diseases is the antinuclear antibody (ANA) test. This test checks the blood for antibodies that attack the nucleus of cells (the center that holds DNA). Most people have a few antinuclear antibodies, but having a large amount may point to an autoimmune disease.14

If your ANA test is negative, then you do not have lupus. If your test is positive, it only means that you have some form of autoimmune disease or a viral infection.14 Your doctor may order more blood work to look for the presence of antibodies that are specific to lupus, such as anti-dsDNA and anti-Sm.15

Additional Testing

If you have a positive ANA test, your doctor will then likely order tests specific to certain types of lupus or to address symptoms you’re having. If you’re having chest pain, your doctor may order a chest x-ray to look for inflammation around the heart or lungs. An echocardiogram (ECG) can also show if your heart has been affected.6

In some cases, lupus attacks the kidneys, making them less effective at clearing out waste from the body. A urine test, or urinalysis, can be done to check how your kidneys are functioning. People with lupus may have extra protein in their urine (known as proteinuria) or leftover bits of dead cells (known as cellular casts).16

Your doctor may also order a biopsy of the skin or kidneys to look at the tissues under a microscope. Taking a closer look can help them determine whether you have lupus or another autoimmune disease or condition.13

Complications from Lupus

Lupus is a disease that affects the entire body, which may lead to other health complications. These can affect the kidneys, heart, lungs, and bones. Some of these complications can go unnoticed, so it’s important to attend your regular checkups to monitor your overall health.

Lupus Nephritis

Lupus nephritis is a kidney condition caused by SLE. Kidney damage is a fairly common complication from lupus — it’s estimated that around 50 percent of adults and 80 percent of children with SLE will develop kidney disease.17 Lupus nephritis tends to develop about five years after the first lupus symptoms appear. Kidney inflammation is hard to notice and isn’t typically painful, so the damage can go unnoticed for many years. Thus, it’s important to have regular blood and urine tests to look for any kidney damage.1

Normally, the kidneys filter out waste and water from the body and help balance mineral and salt levels. However, in lupus nephritis, the kidneys are attacked by the immune system and become damaged. This means they cannot properly filter out unwanted substances from the body, causing them to build up. Symptoms of lupus nephritis include high blood pressure, foamy urine, and swelling in the feet, ankles, and legs (known as edema).17

Heart Disease

Lupus increases the risk of developing heart disease, specifically coronary artery disease (CAD). Many people with lupus also have other risk factors associated with CAD, including high blood pressure, type 2 diabetes, and high cholesterol.1

Chronic inflammation from lupus can also damage the lungs, heart, and circulatory system. Pleuritis is inflammation of the pleura, or the inner lining of the lungs. Pericarditis is inflammation of the pericardium, or the sac that surrounds the heart. Lupus is also known to cause atherosclerosis, or the buildup of cholesterol and fat in arteries. Eventually, this buildup can block blood flow and lead to symptoms of cardiovascular disease.18

Congenital Heart Block

In some cases of neonatal lupus, a congenital heart block can develop in the infant. This condition interferes with the heart’s rhythm, preventing the beat from transferring from the top of the heart to the middle. A heart block may be mild, moderate, or severe, depending on how much the heartbeat is blocked from moving through the heart.7

Osteoporosis

Those with lupus, especially women, are at a higher risk for developing osteoporosis. This condition affects bone density, increasing the chances of a fracture. Lupus medications, such as glucocorticoids, can trigger bone loss. During active flares, you may be less likely to get up and exercise, and this inactivity also increases the risk of osteoporosis. To help prevent bone loss, be sure to eat a balanced diet with vitamin D and calcium, and try to exercise regularly. If you’re taking glucocorticoid medications, talk to your doctor about a bone density test to monitor your bone health during treatment.19

Resources for Living with Lupus

If you’re living with lupus, there are several resources available to help guide you through diagnosis, treatment, and your day-to-day life.