If your symptoms of systemic lupus erythematosus (SLE) are mild or well-controlled, you may find it barely affects your day-to-day life and you may not have complications.

You may also find your SLE symptoms significantly improve with age. Many people who are over 50 often find that their SLE symptoms have eased. In some (but not all) people, SLE may improve after the menopause (when a woman's monthly periods stop, usually at around the age of 50).

However, for some people SLE can be a more serious condition that can sometimes cause life-threatening complications. Some of the possible complications that can be experienced are outlined below.

Cardiovascular disease

Cardiovascular disease (CVD) is a general term for any type of health condition that affects the heart and arteries.

Examples of CVD include:

• high blood pressure (hypertension)
• atherosclerosis - hardening and narrowing of the arteries
• coronary heart disease
• angina  - chest pain due to the heart not receiving enough blood
• heart attack
• strokes

It is estimated that people with SLE are seven to eight times more likely to develop CVD than the general population. The reason for this is that SLE can cause inflammation of your heart and arteries, making it more likely that you will develop CVD.

By taking steps to lower other known risk factors for CVD, you can help compensate for the increased risk of developing CVD as a result of having SLE. These include:

• quitting smoking (if you smoke)
• eating a balanced healthy diet low in saturated fat, sugar and salt and contains plenty of fruit and vegetables (at least five portions a day)
• maintaining a healthy weight
• taking regular exercise - at least 30 minutes a day, three to four days a week (the exercise should be strenuous enough to leave you slightly out of breath)
• if you drink, making sure that you stick to the recommended guidelines for alcohol consumption (see below)

The recommended daily limits of alcohol consumption are:

• three to four units of alcohol for men
• two to three units of alcohol for women

A unit of alcohol is equal to about half a pint of normal strength lager, a small glass of wine or a pub measure (25ml) of spirits.

See the Live Well section about Healthy hearts for more information about how to prevent CVD.

In some people, SLE can cause a number of other heart conditions that are usually less serious such as:

• pericarditis - inflammation of the lining of your heart
• myocarditis - inflammation of the muscles of your heart

Lupus nephritis

Lupus nephritis is a potentially serious kidney disease that is caused by prolonged inflammation of your kidneys as a result of SLE. Lupus nephritis is a common complication of SLE that is estimated to affect around half of people with the condition.

Lupus nephritis tends to develop relatively early on in the course of SLE, usually within five years of receiving a diagnosis.

Symptoms of lupus nephritis include:

• swelling of your feet
• headaches
• dizziness
• blood in your urine
• a frequent need to urinate

In many cases, lupus nephritis does not cause any noticeable symptoms. However, this does not mean that the condition is not dangerous as it can cause damage to your kidney. Lupus nephritis can also cause high blood pressure (hypertension), which if not treated can put you at risk of developing a serious CVD in the long-term, such as a heart attack or stroke.

It is likely you will be referred for regular blood tests so the condition of your kidneys can be carefully monitored.

If you develop lupus nephritis, it can usually be successfully controlled using immunosuppressants such as azathioprine, mycophenolate mofetil or cyclophosphamide.

Other autoimmune conditions

Approximately one in three people with SLE also have another autoimmune condition, such as thyroid disease, Sjogren's syndrome or Hughes syndrome (antiphospholipid syndrome).

Sjogren's syndrome

Sjogren's syndrome is a condition that damages your salivary and tear glands, causing you to have a dry mouth and eyes. It affects one in eight people with SLE. See the Health A-Z topic about Sjogren's syndrome for more information.

Hughes syndrome (antiphospholipid syndrome)

Hughes syndrome (antiphospholipid syndrome) can occur as a secondary condition to SLE or it can occur on its own.

Hughes syndrome causes an increased risk of clots developing in the arteries (leading to strokes and heart attacks) and the veins (leading to deep vein thrombosis).

Women with SLE and Hughes syndrome also have an increased risk of developing complications during pregnancy. They have an increased risk of miscarriage and premature delivery.

Diagnosis of Hughes syndrome (antiphospholipid syndrome) in cases of SLE requires the presence of either vascular and/or pregnancy-related complications together with antiphospholipid antibodies in the blood.

See the Health A-Z topic about Hughes syndrome for more information on this condition.

Pregnancy

SLE does not usually affect fertility, although many people with the condition also have Hughes syndrome (see above), which increases the risks of complications occurring during pregnancy, such as:

• miscarriage
• stillbirth
• premature delivery

Treatments such as aspirin and heparin injections are available, which increase the chance of a successful pregnancy in patients with Hughes syndrome.

There is also a risk that women with lupus will experience a flare-up of their symptoms during pregnancy.

Symptoms of SLE that can develop during pregnancy include:

• hair loss
• swelling of the feet and hands
• facial redness
• anaemia
• muscle, bone and joint pain

Some symptoms may be difficult to distinguish from those related to pregnancy itself, such as anaemia. The risk of flare-ups can usually be reduced by taking anti-malarial medications and appropriate immunosuppressants, such as azathioprine. If necessary, corticosteroids can also be given.

To reduce the risks of complications developing during pregnancy you may be advised to delay your pregnancy until you have gone for six months without experiencing a flare-up of your symptoms and your kidney functions are normal or nearly normal.

While no medication is guaranteed as being safe to use during pregnancy, the medications that are known to be safest are:

• hydroxychloroquine - an anti-malarial medication
• azathioprine - an immunosuppressant
• prednisolone - a corticosteroid

Glossary

• Blood: Blood supplies oxygen to the body and removes carbon dioxide. It is pumped around the body by the heart.
• Blood vessel: Blood vessels are the tubes in which blood travels to and from parts of the body. The three main types of blood vessels are veins, arteries and capillaries.
• Fatigue: Fatigue is extreme tiredness and lack of energy.
• Fever: A fever is when you have a high body temperature (over 38C or 100.4F).
• Heart attack: A heart attack happens when there is a blockage in one of the arteries in the heart.
• Inflammation: Inflammation is the body's response to infection, irritation or injury, which causes redness, swelling, pain and sometimes a feeling of heat in the affected area.
• Kidney: Kidneys are a pair of bean-shaped organs located at the back of the abdomen, which remove waste and extra fluid from the blood and pass them out of the body as urine.
• Lungs: Lungs are a pair of organs in the chest that control breathing. They remove carbon dioxide from the blood and replace it with oxygen.
• Oxygen: Oxygen is an odourless, colourless gas that makes up about 20% of the air we breathe.