Behet's disease can cause a wide range of symptoms, but it's rare for someone with the condition to have all of them at once.

Most peopleexperiencetimes when the symptoms improve (remission) and times when they get worse (flare-ups or relapses).

The main symptoms of Behet's disease are outlined below.

Mouth ulcers

Almost everyone with Behet's disease develops Mouth ulcers . The ulcers look the same as normal mouth ulcers, but can be more numerous and painful. They most often develop on the tongue, lips, gums and the insides of the cheeks.

The ulcers usually heal within a couple of weeks without leaving any scarring, although they'll often return.

Genital ulcers

Like mouth ulcers, recurrent genital ulcers are also a common symptom of Behet's disease.

In men, the ulcers usually appear on the scrotum. In women, they usually appear on the cervix (neck of the womb), vulva or vagina. However, genital ulcers can appear anywhere in the groin area, including on the penis.

The genital ulcers are usually painful and leave scarring in around half of all cases. Men may also experience inflammation (swelling) of the testicles and women may find the ulcers make having sex painful.

Genital ulcers caused by Behet's disease are not contagious and can't be spread through sexual intercourse.

Skin lesions

Many people with Behet's disease also develop skin lesions. A lesion is any type of unusual growth or abnormality that develops on your skin, such as a bump or a discoloured area of skin.

Skin lesions that can occur inBehet's disease include red, tender swellings on the legs called erythema nodosum andmore widespread acne -like spots called pseudofolliculitis.

Skin lesions oftenheal within 14 days, although they may come back frequently. Erythema nodosumlesions may leave permanently discoloured areas of skin.

Inflammation of the joints

Behet's disease affects the joints in up totwo in every threepeople with the condition, causing arthritis -like symptomssuch as pain, stiffness, swelling, warmth and tenderness.

The joints most often affected include the knees, ankles, wrists and small joints in the hands.

Unlike some conditions affecting the joints, permanent joint damage is rare in Behet's disease and symptoms can usually be controlled successfully.

Inflammation of the eyes

Inflammation of the eyes is another common symptom of Behet's disease, occurring in around half of all cases. It often develops very suddenly.

Inflammation often affects the uveal tract, which is a group of connected structures inside the eye. Sometimes both eyes may be affected at the same time.

Inflammation of theuveal tract is known as uveitis and it can cause symptoms that include:

  • painful red eyes
  • floaters (dots that move across the field of vision)
  • blurred vision

In the most severe cases of Behet's disease, inflammation of the eyes can lead to permanent loss of vision .However, this is far less likely with early and appropriate treatment.

Sensitive skin

In some people withBehet's disease, the skin isparticularly sensitive to injury or irritation. This is known as pathergy.

For example, if a needle is used to prick the skin of someone who has pathergy, a large red bump would develop within a day or two that appears out of proportion to the original needle prick.

Gastrointestinal symptoms

Behet's disease can cause inflammation of the stomach and bowel, which can lead to symptoms such as:

  • feeling sick and vomiting
  • abdominal (tummy) pain
  • indigestion
  • loss of appetite
  • diarrhoea with bleeding

Occasionally, the inflammation can cause the bowel to become damaged and bleed. Having blood in your stools is a possible symptom of inflammation of the internal lining of the bowel.

Blood clots

The inflammation of the lining of the blood vessels associated with Behet's disease can sometimes cause blood clots to form.

One of the most common types of blood clot to affect people with Behet's disease is deep vein thrombosis (DVT) , where a blood clot develops in one of the deep veins of the body, usually in the legs.

Symptoms of DVTinclude:

  • pain, swelling and tenderness in one of your legs (usually in the calf)
  • a heavy ache in the affected area
  • warm skin in the area of the clot
  • redness of your skin, particularly at the back of your leg below the knee

DVT often requires immediate medical treatment. If you suspect DVT, go to your nearest accident and emergency (A&E) department immediately.

In people with Behet's disease, careful assessmentis needed to determine if it's safe to use blood thinning treatment for this complication. Treatment to control inflammation is usually more effective.

Cerebral venous thrombosis

A less common type of blood clot associated with Behet's disease is cerebral venous thrombosis (CVT).This occurs when a blood clot develops inside theblood vessels that run through channels located between the outer and inner layer of your brain.

The blood clot can increase the pressure inside your skulland also lead to an interruption of the blood supply to the brain (stroke) .

Symptoms of a CVT include:

  • a severe headache this has been described as a throbbing, piercing, band of pain, or asa very severe pain that suddenly appears out of nowhere
  • slurred speech
  • seizures (fits)
  • hearing loss
  • double vision
  • stroke-like symptoms, such as muscle weakness or paralysis but, unlike most strokes, both sides of the body can be affected

CVT should be regarded as a medical emergency. If you suspect a stroke, dial 999 immediately to request an ambulance.


Inflammation of the blood vessels can cause the walls of your blood vessels to weaken. This causes the walls to bulge outwards as a result of blood pressure. The bulge is known as an aneurysm.

Aneurysms don't usually cause any noticeable symptoms unless the wall of the blood vessel becomes so weak that it enlarges or ruptures. This can place pressure on nearby areas and can sometimes lead to internal bleeding or organ dysfunction.

The symptoms of a ruptured aneurysm can vary depending on where in the body the aneurysm developed. Possible symptoms include:

  • pain in a limb
  • a sudden agonising headache
  • dizziness
  • breathlessness
  • coughing up blood
  • confusion
  • loss of consciousness

Inflammation of the nervous system

Inflammation of the central nervous system (CNS) causes the most serious symptoms associated with Behet's disease.

The symptoms of CNS inflammationusually develop quickly over the space of a few days, and can include:

  • headache
  • double vision
  • loss of balance
  • seizures (fits)
  • partial paralysison one side of the body
  • behavioural or personality changes

General symptoms

It's also common for people with Behet's disease to experience more general symptoms as a result of the condition, including periods of extreme physical or mental tiredness (fatigue). This can affect a person's ability to perform any sort of activity.

Content supplied by the NHS Website

Medically Reviewed by a doctor on 2 Dec 2016