The two most common complications of cavernous sinus thrombosis occur after the infection has passed. These are:
- seizures (fits), which affect around 1 in 10 people
- severe headaches, which also affect around 1 in 10 people
Less commonly, once the infection has passed, another blood clot may occur somewhere else in the body. For example this could be in:
- the legs, which is known as deep vein thrombosis, and affects around 1 in 40 people
- the lungs, which is known as a pulmonary embolism, and affects around 1 in 200 people
- the brain, which would trigger the potentially fatal condition known as a stroke, and affects around 1 in 330 people
Permanently severe visual impairment is another less common long-term complication affecting around 1 in every 160 people.
Complications can also occur if the infection spreads from beyond the cavernous sinuses. These include:
- meningitis, which is an infection of the outer protective layer of the brain and can cause symptoms such as stiff neck, mental confusion and sensitivity to light
- sepsis or blood poisoning, which can cause symptoms such as chills, fast heartbeat and rapid breathing
- blindness
