Causes

CIDP (chronic inflammatory demyelinating polyneuropathy): symptoms, treatment and outlook

CIDP is a rare condition in which the immune system damages the insulating coat of the nerves to the arms and legs. Weakness and numbness build over at least two months. Most people improve with treatment.

Written by the Managing Neuropathy editorial team under the direction of Dr. Tom Biernacki, DPM, FACFAS · Clinical review pending · Last updated 11 October 2026

A hand resting on a metal handrail beside a flight of pale concrete stairs

The short answer. CIDP stands for chronic inflammatory demyelinating polyneuropathy. The immune system attacks myelin, the insulating coat of the nerves outside the brain and spinal cord. Typically, weakness in the hips and thighs as well as the hands and feet, numbness, lost reflexes and poor balance build over at least eight weeks. It is rare and often misdiagnosed. Neurologists treat it with immunoglobulin, steroids or plasma exchange, and most people improve. Weakness spreading over days, or trouble breathing or swallowing, needs emergency care.

What CIDP means

The name describes the disease. Chronic: it worsens for at least eight weeks, steadily or in relapses. Inflammatory: the immune system drives it. Demyelinating: it damages myelin, the fatty insulation around nerve fibers, so signals slow or get blocked. Polyneuropathy: many peripheral nerves are affected, usually on both sides. The 2021 guideline of the European Academy of Neurology and the Peripheral Nerve Society (EAN/PNS) calls it chronic inflammatory demyelinating polyradiculoneuropathy, because the nerve roots by the spine are inflamed too.

How common it is. Estimates vary. A 2019 review pooled 2.81 cases per 100,000 people. A 2026 analysis of US insurance claims found 23.3 per 100,000 in 2023, about 77,000 Americans, though it relied on billing codes, and misdiagnosis is common. People in their 50s and 60s seem more likely to get it, and men more than women, the US Food and Drug Administration (FDA) notes.

What causes it

In most cases no cause or trigger is found. Some follow an infection, and CIDP is linked with lupus, HIV and hepatitis B or C. The link with diabetes is debated: StatPearls (2024) calls uncontrolled diabetes a potential risk factor, but a 2009 Mayo Clinic study found it unlikely to be a major one.

Symptoms, including the first ones

About half of people have typical CIDP (52 percent in a 2024 Japanese national survey); the rest have variants, some mainly in the feet.

Weakness near and far from the trunk, in the hips, thighs and shoulders as well as the hands and feet. Stairs, rising from a chair and buttons get harder. Weakness usually outweighs numbness.
Numbness or tingling in the fingers and toes, and reflexes reduced or lost in all four limbs.
Unsteady walking from poor position sense, and foot drop that makes the toes catch.
Fatigue, and pain in 46 percent at some point, the 2021 guideline estimates.
Less often, facial weakness, double vision or trouble swallowing (10 to 20 percent, says StatPearls; rare, says Cleveland Clinic), and rarely weak breathing muscles.

How it differs from common neuropathy. The usual kind, such as diabetic neuropathy, starts in the toes, creeps up over years and mostly affects feeling. CIDP adds weakness near the trunk and develops over months. How the common pattern behaves. Neuropathy symptoms in full.

CIDP, Guillain-Barré syndrome, MS or an inherited neuropathy?

	What is damaged	How fast	Clues
CIDP	Myelin of the peripheral nerves and nerve roots	8 weeks or more, steadily or in relapses	Weakness near and far from the trunk; reflexes lost
Guillain-Barré syndrome (GBS)	Peripheral nerves and nerve roots, most often their myelin	Hours to days; 90 percent are weakest by the third week	Often after an infection; hospital care; usually one episode
Multiple sclerosis (MS)	Brain and spinal cord, the central nervous system	Relapses, or slow progression; usually begins at 20 to 40	Vision problems; lesions on brain and spinal MRI
Charcot-Marie-Tooth disease (CMT)	Peripheral nerves; inherited	Slowly over years, from the teens or early adulthood	High arches, curled toes; genetic testing

When CIDP starts fast. Up to 13 percent of people with CIDP weaken within four weeks and may first be told they have GBS, the 2021 guideline says. The clue is still worsening more than eight weeks after onset, or relapsing three or more times after first improving.

How CIDP is diagnosed

No single test proves it. Neurologists apply the 2021 EAN/PNS criteria, which revised the older EFNS/PNS criteria.

Nerve conduction studies.
For typical CIDP, a firm diagnosis needs a demyelinating pattern, such as slowed or blocked signals, in at least two motor nerves, plus sensory abnormalities in two nerves. The rules differ for the variants. If fewer nerves qualify, supportive tests can help. What the tests involve.

Blood and antibody tests.
For an abnormal blood protein, glucose, blood count, and kidney and liver function, plus genetic tests if needed. Antibodies to nerve proteins such as neurofascin-155 point instead to an autoimmune nodopathy, which responds poorly to immunoglobulin; rituximab may help.

Supportive tests, if needed.
Raised spinal fluid protein with a normal white cell count, enlarged nerve roots on MRI, or enlarged nerves on ultrasound. A biopsy, most often of the sural nerve, is kept for special cases and can leave a numb patch.

A measured response to treatment.
Improvement on a disability scale and on a strength or sensation measure, such as grip strength.

Misdiagnosis is common: what to ask

The guideline says misdiagnosis commonly occurs. In a 2015 study, 47 percent of 59 people referred with a CIDP diagnosis didn’t meet minimal criteria. A 2021 Dutch study overturned 32 percent of 96 referral diagnoses (97 percent of those people had another neuropathy), while 20 percent of confirmed cases had first been given another diagnosis. Common errors: loose reading of nerve tests, overrating a mildly raised spinal fluid protein, trusting how people felt after treatment, and overlooking weakness near the trunk. Ask:

Do my nerve tests meet the 2021 EAN/PNS criteria?
How will we measure whether treatment works?
Were other causes checked, including diabetes, abnormal blood proteins, inherited neuropathy and nodal antibodies?
If treatment isn’t helping, should a neuromuscular specialist review the diagnosis?

Treatment

Neurologists prescribe and monitor treatment, which may last months or years. For disabling symptoms, the 2021 guideline strongly recommends immunoglobulin or corticosteroids, with plasma exchange similarly effective, then the lowest dose that keeps you stable.

Immunoglobulin, antibodies from donors, given by vein (IVIG) or, to keep CIDP under control, under the skin (SCIG). IVIG side effects include infusion reactions, fever, chills and blood clots.
Corticosteroids, such as daily prednisone or high-dose dexamethasone pulses. They are inexpensive, but long-term use can raise blood sugar and blood pressure, thin the bones and raise the risk of infection, and some people with motor CIDP get worse on them. Don’t stop them suddenly without talking to your doctor.
Plasma exchange, which filters antibodies out of the blood. It can work faster than the others, but symptoms often return. It may be harder to tolerate, needs repeated access to a vein, often by catheter, and is often kept for severe cases or for when the other two haven’t helped.
Efgartigimod alfa with hyaluronidase (Vyvgart Hytrulo), approved by the FDA for adults with CIDP in June 2024. This weekly injection under the skin lowers IgG antibody levels. In the main trial, everyone took it at first, and 221 of 322 adults (69 percent) improved. In those who did, continuing it cut the risk of relapse by 61 percent compared with a placebo. It may raise the risk of infection and can cause allergic reactions.

Outlook, life expectancy and “final stages”

CIDP may settle after one episode, relapse with partial or full recovery in between, or progress slowly. Sources differ on how many improve. StatPearls (2024) says about two-thirds respond to any one standard treatment, 10 to 15 percent respond to none, and nearly 40 percent reach cure or remission. Cleveland Clinic (2023) says about 90 percent improve with treatment, and half relapse. In a 2024 Japanese survey of 1,257 people, 14 percent didn’t respond to first-line treatment, and 18 percent couldn’t walk on their own at their last visit.

Life expectancy. Cleveland Clinic says CIDP isn’t fatal and life expectancy is typically normal. There are no set final stages; fatigue or weakness can linger even after good treatment. How neuropathy can add risk.

Your feet and legs: foot drop, balance and exercise

The 2021 guideline suggests advice on foot care and exercise, and orthoses and physical therapy as needed.

Foot drop is not uncommon and may need a brace to keep the ankle from stiffening, the GBS|CIDP Foundation’s therapy guidelines (posted 2019) say. An ankle-foot orthosis (AFO) holds the foot up; wear supportive shoes with room for it. Foot drop explained. Choosing a brace.
Balance. Weak legs and poor position sense raise the risk of falling; a physical therapist can train balance and walking.
Numb feet. Check your feet, and the skin under any brace, every day. Wear shoes and socks at all times, even indoors. The daily foot check.
Exercise, paced. In a small study of 17 people with CIDP, reported in 2018, 12 weeks of strength and exercise-bike training improved strength by 14 percent and fitness by 11 percent.

Stop rules. Exercising to exhaustion delays recovery, the foundation’s guidelines warn. Start light, ease off at the first signs of fatigue, and don’t push through pain. Tiredness lasting more than 12 to 24 hours probably means you did too much. Report new or spreading weakness or numbness, and ask a physical therapist to plan your program. Balance and strength exercises.

When to get help urgently

Go to an emergency department, or call 911, for weakness spreading over hours or days, new facial weakness, a fall with new weakness, or any trouble breathing or swallowing: possible Guillain-Barré syndrome or a fast CIDP flare.
Call 911 for sudden numbness or weakness in the face, an arm or a leg, especially on one side, sudden trouble speaking or sudden loss of balance: possible stroke. Call too after a fall that may have hurt your head, neck, back or hip, or if you can’t get up.
Go to an emergency department, or call 911, for new numbness around the groin or bottom, or new bladder or bowel trouble: possible pressure on the nerves at the base of the spine.
Call 911 for chest pain or sudden breathlessness, and see a doctor the same day for a swollen, painful leg: possible blood clots, a risk with immunoglobulin.
Get seen the same day for a warm, red, swollen foot without an injury (possible Charcot foot or infection; keep weight off it), or a cut or blister on a numb foot that turns red, warm, swollen or painful, drains, comes with a fever, or hasn’t started to heal after a few days.
See your doctor promptly for weakness, numbness or unsteadiness building over weeks. Early treatment can stop CIDP progressing and prevent lasting nerve damage. If you are being treated, call your neurologist before your next visit if weakness returns or worsens.

Common questions

What does CIDP stand for?

Chronic inflammatory demyelinating polyneuropathy, also called chronic inflammatory demyelinating polyradiculoneuropathy. It is a long-lasting immune attack on myelin, the insulating coat of the nerves outside the brain and spinal cord, causing weakness, numbness and lost reflexes that build over at least eight weeks.

What are the first symptoms of CIDP?

Often tingling or numbness in the fingers and toes with weak legs: trouble with stairs or rising from a chair, or a foot that drops and catches. Balance worsens and reflexes fade. Unlike common neuropathy, weakness reaches the hips and thighs, building over at least eight weeks. See a doctor promptly if this is happening.

What is the difference between CIDP and MS?

Both involve an immune attack on myelin. Multiple sclerosis affects the brain and spinal cord, usually begins between ages 20 and 40, often causes vision problems and shows on MRI. CIDP affects the peripheral nerves to the arms and legs, causing weakness, numbness and lost reflexes; nerve conduction studies show it.

What is the life expectancy with CIDP?

Usually normal. Cleveland Clinic says CIDP isn’t a fatal condition and people with it typically have the same life expectancy as people without it. The risks come from complications: falls, infections linked to long-term treatment and, rarely, weak swallowing or breathing muscles.

What are the final stages of CIDP?

There are no set final stages. CIDP may settle, relapse and recover, or progress slowly, and most people improve with treatment, which some can later lower or stop. In a 2024 Japanese survey, 18 percent couldn’t walk on their own at their last visit. Weak swallowing or breathing is rare and an emergency.

This page is general education and is not a diagnosis, a treatment plan, or a substitute for care from your own clinician. Clinical review by Dr. Biernacki is pending; the review date will be shown here once complete.

For our Michigan neighbors

Tripping, weak ankles
or numb feet?

An examination of strength, reflexes and feeling in the feet can show what needs a neurologist, and a brace or better shoes can make walking safer meanwhile. Dr. Biernacki’s Michigan practice can start there.

Explore Michigan appointments →

Everywhere else, take this page to your own clinician.

Dr. Tom Biernacki, DPM, FACFAS

Dr. Tom Biernacki, DPM, FACFAS is a double board-certified foot and ankle surgeon (ABFAS and ABPM) and a Fellow of the American College of Foot & Ankle Surgeons. He is the founder of Balance Foot & Ankle in Howell and Bloomfield Township, Michigan, where peripheral neuropathy, diabetic foot risk and loss of protective sensation are part of his weekly clinic. His patient education videos have drawn more than 950,000 subscribers on YouTube. Managing Neuropathy is written by its editorial team under his direction, to put the explanation he gives in the exam room in front of the people who cannot get to one — including when a product is worth buying and when it is not.