Chronic inflammatory demyelinating polyneuropathy (CIDP) is a rare neurological disorder that causes inflammation of your body’s nerves. Though your immune system generally keeps you healthy by fighting off germs, with CIDP, your immune system does not recognize parts of your nerves and attacks them.

Specifically, the immune system mistakenly attacks your nerves’ protective myelin. When the myelin is damaged or removed, messages transmitted to and from the brain are disrupted and may never make it to their final destination.

Over time, this may cause gradual weakness, numbness and a loss of feeling in your arms and legs. If left untreated, CIDP can cause permanent damage to the nerves.