Overview
Cryoglobulins are proteins that clump in cold temperatures and block small blood vessels.
Most cases are linked to hepatitis C, which can be cured.
Symptoms
Common signs:
- Purple spots on legs
Less common
- Joint pain
- Numbness
- Fatigue
Look up a symptom: Numb or tingling leg or foot · Pain in many joints · Small, bright red raised dots on the skin
When to get medical care
Call 911This isn't an emergency by itself. Call 911 for trouble breathing, chest pain, or fainting.
Get care todayNew or worse symptoms, or symptoms with fever.
See a doctor soonSymptoms that last or keep coming back.
Causes
Immune.
Does it spread or run in families?
- It isn't contagious. You can't catch it from someone else.
Who is more likely to get it
- Hepatitis C
- People with hepatitis C: The most common cause
- Women 40 to 60: Most common
Possible complications
- Kidney damage: Can lead to kidney failure
- Peripheral neuropathy: Numbness and tingling
Diagnosis
A clinician asks about your symptoms and may order tests.
The exam
A physical exam.
Tests
Tests, if needed:
- Blood tests:
Treatment
Treatment depends on the cause and how severe it is.
Self-care
- Keep warm
- Keep hands and feet warm
- Treat hepatitis C
Which doctor treats this
- Start with your primary care provider (family doctor or internist).
- They may send you to a rheumatologist (joint and immune system doctor).
Living with it
Support groups and helplines
- Genetic and Rare Diseases Information Center (GARD): Free NIH information on rare diseases, including where to find experts and patient groups.
- National Organization for Rare Disorders (NORD): Patient groups, help finding care, and aid programs for rare diseases.
Children, pregnancy, and older adults
- Adults with hepatitis C: Higher risk.
Pregnancy and breastfeeding
- If you're pregnant or planning to be, tell your prenatal provider about this condition.
- Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
- Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
- Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.
Outlook
Treating the cause often helps.
Getting ready for your visit
Bring a list of your symptoms and medicines.
What to bring
- A list of your medicines and supplements
- Notes on when symptoms started and what makes them better or worse
Questions to ask
- What's causing this?
- What treatment do you recommend?
Research studies
Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.
Sources
Last updated 2026-11-12.