The term “compression neuropathies” is a generic term used to describe a group of nerve problems characterized by an increase of pressure around the nerve.
A nerve travels from exit tunnels at the spine all the way down to the limbs reaching the skin and muscles in the arms and legs. This can be compared to a highway that connects to distant places.
A highway has traffic in both directions and it has many exits and tunnels. The same thing happens with your nerves, they travel through many tunnels and they have many exits. They also connect two distant places; they carry the nerve signals (or "traffic") up and down from your brain and spinal cord to your arms and legs and from your arms and legs up to the spinal cord and brain. In the case of a highway, it can be affected by a “traffic jam” under its tunnels, exits or anywhere else. The nerves can be affected by a traffic jam causing a delay or no motion of the nerve signal (traffic) at all.
On the highway, the traffic jam causes many things like overheating of the engine of the cars, frustration and stress of the drivers. Similarly, when a nerve is compressed or jammed, it gets frustrated and stressed. Then, the nerves start telling us that something is wrong by producing symptoms, including tingling, numbness, pain, decreased sensation and sometimes nocturnal (nighttime) symptoms.
Where Compressed Nerves Occur
There are many places where the nerve can be compressed or jammed. For instance, in your upper limbs: in your hands (the carpal tunnel and Guyon tunnel); around your elbow (the pronator tunnel and the cubital tunnel); around your shoulder (below the collarbone or above it); finally at your neck, where the nerve exits the spinal cord. In the same manner, a nerve can be jammed in your lower limbs: at your ankle (tarsal tunnel syndrome); around your knees (peroneal nerve); and around your hips (piriformis syndrome).