A backache that won’t quit. Exhaustion that sleep doesn’t fix. A chest infection you can’t seem to shake. Each one is easy to blame on age, stress, or a bad mattress, which is why multiple myeloma symptoms so often go unrecognized for months.
Multiple myeloma is a cancer of plasma cells, the white blood cells that make antibodies. It is rare, with roughly 36,000 Americans diagnosed each year, so it’s seldom the first explanation anyone reaches for.[1] What gives it away is rarely one dramatic symptom. It’s the pattern: what persists, what changes, and what starts showing up together.
Why one disease causes so many symptoms
Plasma cells live in your bone marrow. In myeloma, abnormal ones multiply, crowd out the healthy cells that make blood, and release excess M protein, either a whole antibody, free light chains, or both. They also signal bone-dissolving cells to work overtime.
Crowding, protein overload, and bone damage: nearly every symptom below traces back to one of these. Doctors group the classic complications under the acronym CRAB: high calcium, renal (kidney) impairment, anemia, and bone lesions. They rarely all appear together.
Bone pain and fractures
Bone pain is one of the most common symptoms, affecting roughly six in ten people at diagnosis.[2] It tends to settle in the back, ribs, or hips, flaring with movement at first and sometimes becoming a constant ache that disturbs sleep. Back pain is common, and persistence is one clue: pain that lingers for weeks without an obvious cause, or keeps getting worse, deserves a closer look.
Weakened bone can also give way under surprisingly little strain: a cough, a twist, a grocery bag. Compression fractures in the spine can make you lose height or round your back. Sometimes a fracture is the first clue.
Fatigue, breathlessness, and pale skin
Fatigue is the symptom people explain away fastest. When crowded marrow can’t keep up, red blood cell production falls, and roughly seven in ten people are anemic by the time myeloma is found. The tiredness feels less like a long week and more like walking through wet cement: ordinary tasks cost more effort, and rest doesn’t fully restore you. It often travels with breathlessness on stairs, dizziness, a racing heartbeat, or unusual paleness.
Infections that keep coming back
Myeloma turns down your normal antibody defenses even as abnormal protein piles up. A busy protein factory can still leave you poorly protected. Watch for repeated chest, sinus, or urinary infections, shingles, or infections that take unusually long to clear. One cold means little. A string of them deserves a conversation.
High calcium: thirst, constipation, and brain fog
As bone breaks down, calcium spills into the bloodstream. High calcium (hypercalcemia) can bring intense thirst, frequent urination, nausea, constipation, and muscle weakness. At higher levels it clouds thinking or causes unusual sleepiness, which families often write off as dehydration or “just getting older.” It’s a serious but treatable metabolic problem.
Kidney trouble
The kidneys pay a quiet price. Free light chains can damage them, partly by forming clumps that block tiny tubes inside the kidneys. Nearly one in five people already have significantly reduced kidney function at diagnosis. The catch is silence: early damage often causes no obvious symptoms. Later signs include swelling around the ankles or eyes, itching, and passing less urine. Foamy urine can occur, but it has many other causes.
Kidney function sometimes improves with prompt treatment, which is a strong reason not to wait. NSAIDs such as ibuprofen can worsen kidney injury, especially with dehydration, so ask your doctor before using them if kidney problems are suspected.
Less common signs that still matter
Myeloma can also leave quieter clues:
- Numbness, tingling, or burning in the hands and feet
- Easy bruising or frequent nosebleeds
- Unexplained weight loss
- A lump or swelling over or near a bone
- Rarely, headaches or blurred vision from unusually thick blood (hyperviscosity)
When there are no symptoms
A quiet body doesn’t always mean a quiet disease. Routine tests sometimes uncover MGUS (monoclonal gammopathy of undetermined significance) or smoldering myeloma, where abnormal plasma cells or M protein are present, but the criteria for active myeloma are not met.
MGUS isn’t cancer, and most people who have it never develop myeloma. Each year, about 1 in 100 goes on to develop myeloma or a related condition. Smoldering myeloma is riskier, around 1 in 10 a year at first, though the odds vary widely from person to person.[3] Both are usually monitored, and since late 2025 there’s an FDA-approved treatment for high-risk smoldering myeloma.[4] Follow-up matters even when you feel perfectly well.
Who should stay extra alert
Myeloma becomes more common with age; the median age at diagnosis in the US is 69. It is also more common in men, in people with excess body weight, and in those with a parent or sibling who has myeloma. US rates are more than twice as high in Black people as in White people. These factors shift the odds, but symptoms deserve attention in every group.
When to see a doctor
Persistent, unexplained bone pain, unusual fatigue, or recurring infections deserve an appointment, even if only one is present. Write down when symptoms started, how they affect your day, and which medicines you take. Usually there is a more ordinary explanation. The appointment is how you find out which one is yours. Either way, symptoms are signals, not verdicts, and listening to them early is one of the most useful things you can do.
Red flags: get help now
Seek emergency care, or call your local emergency number, for:
- New leg weakness, trouble walking, numbness, or loss of bladder or bowel control, especially with back pain, which can signal spinal cord compression
- Severe confusion or difficulty staying awake
- A major drop in how much urine you pass, especially if it is almost none
- Severe shortness of breath, or stroke-like symptoms such as facial droop, slurred speech, or one-sided weakness
How doctors confirm it
Routine blood tests can reveal anemia, high calcium, or reduced kidney function, but they don’t directly test for M protein. If myeloma is suspected, doctors order serum protein electrophoresis, immunofixation, and a serum free light chain assay, with urine tests when needed. If your symptoms fit and nobody has run these, it’s reasonable to ask.
No single result settles the question. An abnormal protein level alone doesn’t confirm cancer, and a normal electrophoresis can miss light-chain-only disease, which is why the free light chain test is part of the panel. A bone marrow biopsy checks plasma cell numbers and genetic changes, while low-dose whole-body CT, MRI, or PET/CT can spot bone damage that plain X-rays miss.
Doctors then weigh everything together. Under current criteria, specific bone marrow findings, free light chain results, or MRI changes can establish active myeloma before organ damage appears.
A diagnosis isn’t the end of the story
Myeloma remains incurable for most people, but it no longer looks the way it did a generation ago. Five-year survival in the US has climbed from about 25 percent in the 1970s to around 64 percent today, and many people live far longer.[6] Age, overall health, the biology of the disease, and how it responds to treatment still shape individual outcomes.
Options include proteasome inhibitors, immunomodulatory drugs, anti-CD38 antibodies, stem cell transplant, and, for some relapsed cases, CAR-T cell therapy or bispecific antibodies.[7] A myeloma specialist can help match the plan to you, and a second opinion at a major cancer center is reasonable. For a closer look at how each option works, see our guide to multiple myeloma treatment.
The International Myeloma Foundation, the Multiple Myeloma Research Foundation, and Myeloma UK offer education and support. The next conversation is about the plan: how to control the disease, protect your organs, and keep doing the things that matter to you.
Medical References
Update History
Supporting evidence reviewed for accuracy and currency.
Originally written by Dr. Rahul Kushwaha.
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