Causes and Symptoms of Lupus

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Causes of lupus

Various factors have an influence on the development of lupus. Studies suggest that genetics play an important role, but is not an absolute determining factor.

There are several genes that lead to an individual to having a predisposition for the disease, but does not necessarily have to develop it. There are other factors that influence and contribute to the onset of this disease, such as hormonal or environmental factors. For example, oestrogens, infections, emotional and physical stress, pregnancy, various drugs, and the ultraviolet light of solar radiation can trigger the activity of the disease and the start of the signs and symptoms.

Symptoms of lupus

The symptoms of lupus vary depending on the individual and the form in which they present. It can affect practically any organ, for this reason it is said that it is systemic, and the symptoms may appear and disappear. When they appear they are called flare-ups. These flare-ups, different in each patient, can be severe or mild in intensity and duration and are combined with periods of remission, during which the patient is asymptomatic.

The symptoms of the disease arise from its inflammatory basis as well as the complications caused by the specific involvement of the different organs and systems. During a flare-up of the active disease, the most common discomforts are symptoms similar to the flu (fever, fatigue, loss of weight, headaches and muscle and joint pains).

Patient with joint pain undergoing radiography

Muscular and skeletal signs and symptoms. As much as 95% of the patients mention joint pain without signs of inflammation, which makes this the most common symptom of this disease. Joint involvement is usually symmetric and often affects the small joints. These symptoms last for between 12 and 48 hours, although, sometimes, they are prolonged for up to 7 or 10 days, and they resolve without leaving sequelae.

The joint disease of lupus differs from rheumatoid arthritis in one important aspect: in lupus it is very rare that the joints are damaged. The appearance of muscle weakness is relatively common, as is muscle pain and muscle inflammation.

Man with skin blemishes

Skin manifestations. When the lupus affects the skin, it is known as cutaneous lupus erythematosus (CLE). Occasionally, CLE is the initial expression of the systemic disease. The lesions may be localised (only on one area of the skin) or generalised (over almost all the body).

Thermometer with a danger signal indicating fever

Fever. It is one of the most common manifestations. There is no characteristic pattern and may be as night sweats and moderate, remitting and, sometimes, elevated and including shivering.

Closed stomach, lack of appetite and anorexia

Anorexia or loss of appetite.

Scale with a down arrow indicating a weight loss

Weight loss. 

Tired woman, sweating

Tiredness (asthenia).

Lung and heart

Heart and lung manifestations. When lupus inflames these organs , it affects, in particular, the membrane linings of the heart (the pericardium) and the lungs (the pleura), which leads to pericarditis (40% of patients) and pleuritis. The two conditions have similar symptoms: Pain in the chest and, sometimes, fever. In general, they do not usually cause any significant problem and respond well to simple medical treatment. On other occasions, the lungs or heart valves, or any of the cardiac structures may be affected. This may lead to respiratory or heart failure. Although these problems are serious, they are usually very rare in individuals with lupus and easily respond to treatment. 

Kidneys and urinary system

Renal manifestations. The kidney lesion caused by lupus is called lupus nephritis. Lupus nephritis causes inflammation and, subsequently, scarring of the small blood vessels that filter body waste in the kidney (glomerulae), which can affect its function. The majority of patients have a favourable outcome in the long-term, but it is likely that they may need to take medications for many years, and even the patients that have few flare-ups or symptoms must undergo regular check-ups indefinitely.

Person holding a hand to his head with a symbol of a lightning bolt above it indicating a headache

Neuropsychiatric manifestations. It is practically impossible to know with certainty the frequency that lupus affects the brain. This is because headaches, depression, or situations of mild hyperactivity, are very common in the general population and may be due to a mild brain inflammation due to the lupus or to many other circumstances. Furthermore, it is also possible that a depression may be “reactive” to the same disease. The patient is not depressed due to the lupus inflammation, but the fact of having lupus causes anxiety and depressive symptoms. In much more rare situations, there may be other symptoms such as behavioural changes, epilepsy, etc., which have to be appropriately treated.

Woman with abdominal pain

Gastrointestinal and liver manifestations. Little is known about the gastrointestinal manifestations of lupus, mainly due its low frequency, although this does not mean they are unimportant. The presence of mouth ulcers is a common sign in lupus and is one of the criteria that classify this disease. The gastrointestinal symptoms may include nausea, vomiting, difficulty in swallowing, abdominal reflux and pain. In patients with lupus, an increase in the size of the liver (hepatomegaly) is common (30-50%), as well as changes in the liver enzymes (30-60%).


Haematological manifestations. Haemolytic anaemia (destruction of the red cells), leukopenia, lymphopenia, and thrombocytopenia, that is to say, a decrease in the number of red cells, lymphocytes and platelets are classification criteria of lupus. Manifestations such as autoimmune haemolytic anaemia and thrombocytopenia are common and, sometimes, can precede the rest of the manifestations of lupus by several years.

Eye with a lightning bolt above it, symbolising pain

Eye manifestations. Lupus can affect any structure of the eye, of which retinal vascular manifestations are the most common. In the majority of occasions, they do not lead to loss of visual acuity. Retinal occlusive disease is a serious complication that can cause temporary or permanent blindness. The appearance of conjunctivitis in periods of clinical activity has also been reported. Dry eye is common and is due, on many occasions, to the co-existence with Sjögren syndrome.

Substantiated information by:

Claudia Castrillo
Gerard Espinosa Garriga
José-Manuel Mascaró Galy
Luis F Quintana Porras
Núria Baños López
Ricard Cervera Segura
Roser Ventura Roca

Published: 20 February 2018
Updated: 1 June 2023

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