“Pinching” a nerve by putting too much pressure on it. For example, the sciatic nerve may be painfully compressed by a ruptured disc in the lower spine, causing sciatica. Pressure neuropathy is also called nerve compression.
In pressure neuropathy there is excessive pressure on a nerve root or a peripheral nerve leading to ischemia (not enough oxygen due to poor blood supply). The response includes edema (swelling) above and below the pressure point. If the pressure continues, fibrosis tends to develop.
Aside from sciatica, the pressure neuropathy syndromes include the carpal tunnel syndrome due to pressure on the median nerve in the carpal tunnel near the wrist, compression of the ulnar nerve at the elbow, and a condition called meralgia paresthetica due to compression of the lateral cutaneous nerve of the thigh.
- Pressure sore
A sore area of skin that develops when the blood supply to it is cut off for more than two to three hours due to pressure on it and lack of movement. As the skin dies, the pressure sore first appears as a red painful area, which in time turns purple. Left untreated, the skin […]
- Pressure urticaria
An uncommon type of hives (urticaria) that occurs after the skin has been under pressure, often the feet after standing or the buttocks after sitting for a long time or areas where clothing is tight. The hives may begin hours after the pressure on the skin has ceased. The hives last 8 to 72 hours […]
- Pressure, intraocular
The pressure created by the continual renewal of fluids within the eye. The intraocular pressure is increased in glaucoma. In acute angle-closure glaucoma, the intraocular pressure rises because the canal into which the fluid in the front part of the eye normally drains is suddenly blocked. In chronic glaucoma, there is a gradual imbalance between […]
- Pressure, low blood
Any blood pressure that is below the normal expected for an individual in a given environment. Low blood pressure is also referred to as hypotension. Low blood pressure is a relative term because the blood pressure normally varies greatly with activity, age, medications, and underlying medical conditions. Low blood pressure can result from conditions of […]
The proportion of individuals in a population having a disease or characteristic. Prevalence is a statistical concept referring to the number of cases of a disease that are present in a particular population at a given time, whereas incidence refers to the number of new cases that develop in a given period of time.