Multiple myeloma is a cancer of the plasma cells, the immune cells inside bone marrow that normally produce antibodies. When one plasma cell clone multiplies without control, it crowds out healthy marrow and floods the blood with a single abnormal antibody known as an M protein. That protein, and the damage it slowly causes to bone and kidneys, explains why the disease is often first suspected from a routine laboratory panel rather than from a dramatic symptom.
In this article you will learn how the disease develops, which symptoms deserve attention, which blood and urine markers a hematologist reviews, how staging and treatment work today, and what recent research has changed. Every marker described here belongs to a work-up led by a physician.
What multiple myeloma is, in plain terms
Plasma cells are the final form of B lymphocytes, the white blood cells that manufacture antibodies against infection. Healthy marrow holds a diverse population of them, each producing a slightly different antibody. In myeloma, one plasma cell acquires genetic changes, copies itself again and again, and all of its descendants make the same single antibody or antibody fragment, which serves no useful purpose.
Two problems follow. The expanding clone occupies space that healthy blood production needs, so red cells, infection-fighting white cells and platelets fall. Meanwhile the abnormal protein filters through the kidneys, and the tumor releases signals that dissolve bone faster than the body can rebuild it.
How a normal plasma cell becomes a myeloma cell
The first genetic events usually switch on growth genes inside the plasma cell, through chromosome swaps or extra copies of part of chromosome 1. Further changes accumulate over years, which is one reason myeloma is largely a disease of later life. Some, such as the loss of a region on chromosome 17, mark a more aggressive form and influence which treatment a specialist recommends.
MGUS and smoldering myeloma, the quiet stages before
Nearly every case is preceded by monoclonal gammopathy of undetermined significance, usually shortened to MGUS: a small amount of M protein with no organ damage. MGUS is common, and most people who have it never develop a blood cancer. Smoldering myeloma sits between MGUS and active disease, with more abnormal plasma cells in the marrow but still no organ damage. The distinction matters because it decides whether a person is monitored or treated.
Symptoms and early signs of multiple myeloma
Early myeloma frequently causes nothing at all, and a good number of diagnoses begin with an unexpected laboratory result. When symptoms do appear, they come from the four kinds of organ damage that specialists group under the letters CRAB.
The CRAB pattern doctors look for
- Calcium: calcium released from dissolving bone, causing thirst, frequent urination, constipation, nausea and mental fog.
- Renal: reduced kidney function, often silent at first and detected only on a blood test.
- Anemia: a low red cell count producing tiredness, breathlessness on exertion and pallor.
- Bone: pain in the spine, ribs, chest or hips, and fractures after minor strain.
Signs that are easy to blame on something else
Because these complaints are so ordinary, the diagnosis is often delayed. Persistent back pain attributed to wear and tear, repeated chest or urinary infections, unexplained weight loss, tingling in the feet, and fatigue that rest does not fix are all worth raising with a physician, especially when several occur together. Marrow crowding commonly produces anemia, which is why an unexplained low red cell count in an older adult is usually investigated rather than simply treated with iron.
Causes and risk factors
Nothing a person does causes myeloma, and it cannot currently be prevented. Research has identified factors that raise the statistical likelihood of developing it, not the certainty.
- Age: most diagnoses occur after sixty, and the median age sits in the late sixties.
- Sex: men are diagnosed somewhat more often than women.
- Ancestry: incidence is about twice as high in Black Americans as in white Americans, and MGUS also tends to appear earlier.
- Family history: a parent or sibling with myeloma or MGUS raises risk modestly.
- An existing MGUS or smoldering myeloma, which is the strongest single predictor.
- Obesity, and certain occupational or environmental exposures, for which the evidence remains less settled.
Mayo Clinic publishes a patient-facing summary of multiple myeloma risk factors.
How doctors diagnose multiple myeloma
Diagnosis rests on three pillars: laboratory tests that detect the abnormal protein and its consequences, a bone marrow sample that counts the abnormal plasma cells, and imaging that looks for bone damage. No single result is decisive.
The blood and urine markers used in the work-up
The work-up usually opens with routine bloodwork: a hematologist orders a complete blood count. Protein studies and chemistry follow. The table below explains what each test contributes.
| Test | What it measures | Why it matters in myeloma |
|---|---|---|
| Complete blood count | Red cells, white cells and platelets | Detects the anemia and low counts caused by marrow crowding |
| Serum protein electrophoresis | The size of each protein band in blood | Reveals a single sharp spike, the M protein, usually in the gamma zone |
| Immunofixation | Which antibody type the spike belongs to | Names the exact class, for example IgG kappa |
| Serum free light chains | Antibody fragments circulating unattached | Finds myeloma that makes fragments only, and tracks response to treatment |
| Total protein and albumin | Overall protein balance in serum | A high total protein with a low albumin often points toward a monoclonal protein |
| Calcium | Calcium circulating in blood | High values signal active bone breakdown and need urgent review |
| Creatinine and eGFR | Kidney filtering capacity | Worsening values suggest light chain injury to the kidneys |
| Beta-2 microglobulin and LDH | Tumor burden and cell turnover | Used together with genetics to assign a stage |
| 24-hour urine protein with electrophoresis | Protein lost in urine over a full day | Detects light chains passing through the kidneys |
Several of these lines will already look familiar from ordinary checkups. The count panel reports hemoglobin levels, and a basic chemistry panel measures total protein. The same chemistry panel reports total calcium, while kidney monitoring follows serum creatinine. Laboratories additionally calculate the estimated glomerular filtration rate.
The protein studies are the part most people have never seen before. Serum protein electrophoresis separates blood proteins into bands and quantifies the gamma globulins fraction, where most M proteins appear. The same trace also reports the beta-2 globulins fraction, where a smaller number of them sit. When the kidneys are involved, the team may request a 24-hour urine protein collection.
Bone marrow biopsy and imaging
A marrow sample, taken from the back of the hip under local anesthetic, shows what percentage of the marrow consists of clonal plasma cells and allows genetic testing of those cells. Imaging has moved on from plain X-rays: whole-body low-dose CT, MRI or PET-CT finds bone lesions far earlier.
What the diagnostic criteria actually require
A 2024 practice update from a Mayo Clinic hematologist sets out the modern definition: at least ten percent clonal plasma cells in the marrow, or a biopsy-proven plasma cell tumor, plus at least one myeloma-defining event. Those events are the CRAB damage described above, or one of three biomarkers: sixty percent or more clonal plasma cells, a very high ratio between the involved and uninvolved free light chains, or more than one focal lesion on MRI. The biomarker route lets treatment begin before organ damage occurs.
Staging
Staging uses the Revised International Staging System, which combines albumin, beta-2 microglobulin, LDH and the genetic profile of the plasma cells into three stages. A stage is a planning tool and a statistical average, not a forecast for any one person.
Treatment options today
First-line combinations
Modern induction therapy combines three or four drug classes that attack the plasma cell from different angles: a proteasome inhibitor such as bortezomib, an immunomodulatory drug such as lenalidomide, a steroid, and increasingly an antibody aimed at the CD38 marker on the plasma cell surface. These are given in cycles over several months and are largely outpatient treatments.
Stem cell transplant
For fit patients, high-dose chemotherapy followed by a transplant of the patient’s own previously collected stem cells remains a standard consolidation step. The returned cells rescue the marrow after chemotherapy; they are not a graft from a donor. Some people with standard-risk disease now collect their stem cells and postpone the transplant until a first relapse.
When the disease returns
Myeloma is usually a relapsing condition, and later treatments are chosen from a growing menu. Two newer classes target BCMA, a protein on the myeloma cell surface: CAR T-cell therapy, in which a patient’s own T cells are re-engineered to recognize it, and bispecific antibodies, which physically link a T cell to a myeloma cell.
Supportive care that matters as much as the anti-cancer drugs
- Bone protection with bisphosphonates or denosumab, plus radiation to a painful lesion when needed. Myeloma bone disease can mimic osteoporosis, although the treatment goals differ.
- Kidney protection: generous fluids, avoidance of anti-inflammatory drugs and contrast agents where possible, and rapid reduction of the light chain level. Untreated light chain deposits can cause chronic kidney disease.
- Infection prevention through vaccination, and sometimes preventive antibiotics or antibody replacement.
When to see a doctor
None of the following proves myeloma. All of them justify an appointment.
- Bone pain in the back, ribs or hips lasting more than a few weeks, waking you at night, or following a trivial injury.
- A fracture after a fall that should not have broken anything.
- Fatigue with breathlessness, or a low red cell count found on a routine test.
- Repeated infections within a short period.
- Intense thirst, frequent urination, constipation and confusion occurring together, which can indicate a high calcium level and warrants same-day assessment.
- A creatinine level that is climbing, or persistently foamy urine.
- A laboratory report mentioning a monoclonal protein, a paraprotein, or an abnormal free light chain ratio.
Bring your previous laboratory reports to the appointment. A single value in isolation says little; the direction of travel over months says a great deal.
Living with multiple myeloma
Survival has improved substantially over the last two decades, and many people now live with myeloma as a long-term condition managed in alternating phases of treatment and remission. Monitoring is mostly laboratory-based: the M protein level or the free light chain level is measured at intervals, alongside blood counts, calcium and kidney function. A rising marker opens a discussion, not an automatic change of treatment.
Practical measures help. Weight-bearing activity adapted to bone strength, steady hydration, vaccination, a dental review before starting bone-protecting drugs, and a clear list of medications to avoid all reduce complications. Fatigue and the emotional weight of a long-term cancer diagnosis are legitimate reasons to ask for support rather than things to endure quietly.
Latest scientific advances
Research over the last three years has changed how this disease is detected, monitored and treated. Here is what the most relevant work found, and what it means in practice.
Free light chain reference ranges were too wide
A nationwide screening study in Iceland measured free light chains in tens of thousands of adults and found that the reference intervals laboratories have long used flag far more people than necessary. With revised intervals adjusted for age, the number of people labeled as having a light chain abnormality fell by more than four in five, and none of those reclassified as normal went on to develop a blood disorder over roughly five years of follow-up.
What this means for you: an out-of-range free light chain result on a single report is frequently not a sign of cancer, particularly in older adults and in people whose kidneys filter less efficiently. It is a reason for your doctor to look at the whole picture, not a reason to assume the worst.
MGUS is common, and testing works best when it is targeted
A 2025 review in a leading internal medicine journal concluded that MGUS affects close to one adult in twenty and that the chance of progressing to a malignant disease is roughly half a percent to one percent each year. The authors argue that testing for an M protein should be reserved for situations where a plasma cell disease or related organ damage is genuinely suspected.
What this means for you: if a test found an M protein, the most likely outcome by far is stable, symptom-free monitoring. Low-risk MGUS can usually skip a bone marrow biopsy and advanced imaging altogether.
Smoldering myeloma: watch closely, or treat early
A 2026 review from a major cancer center set out how specialists now separate low-risk smoldering myeloma, which behaves much like MGUS, from high-risk smoldering myeloma, where close to half of patients progress to active disease within two years. For the high-risk group, both early treatment and careful surveillance are considered reasonable, and the choice is made with the patient after weighing benefits against side effects.
What this means for you: a smoldering diagnosis is not a treatment emergency, but the risk category assigned to it genuinely changes the plan, which is why the initial work-up is so thorough.
Four-drug combinations for newly diagnosed disease
A large randomized trial published in 2024 added an anti-CD38 antibody, isatuximab, to the standard three-drug regimen in patients who were not candidates for a transplant. A randomized trial is one in which participants are assigned to treatments by chance, which is what makes the comparison trustworthy. The fourth drug kept the disease under control considerably longer, and a separate trial reported in 2025 reached a similar conclusion with daratumumab.
What this means for you: four-drug induction is now a common starting point, including for older adults who would once have been offered less. It also means more appointments and more side effects to track.
Laboratory results are starting to steer treatment intensity
In a 2025 trial, patients whose marrow showed no measurable residual disease after a strong four-drug induction, meaning fewer than one myeloma cell per hundred thousand normal cells using a very sensitive technique, did just as well with additional cycles of the same drugs as with a stem cell transplant.
What this means for you: highly sensitive laboratory monitoring is moving from research into decision-making. These results are recent and need longer follow-up before practice changes everywhere, but the direction is toward treatment tailored to measured response rather than to protocol alone.
Kidney damage recovers better when it is caught early
A 2024 review of kidney disease in myeloma emphasized that the most common form of kidney injury comes from light chains precipitating inside the kidney tubules, that this injury often reveals the myeloma itself, and that kidney recovery depends heavily on how quickly and how deeply the free light chain level is brought down.
What this means for you: a kidney result drifting in the wrong direction deserves prompt attention rather than a wait-and-see approach, and free light chain measurements are the marker most closely tied to whether kidney function returns.
Glossary
| Term | Definition |
|---|---|
| Plasma cell | A mature white blood cell in bone marrow whose job is to produce antibodies against infection. |
| M protein | Also called a monoclonal protein or paraprotein. The single identical antibody made in large amounts by a myeloma clone. |
| Free light chains | Small antibody fragments circulating without being attached to a complete antibody. Measured in blood as kappa and lambda. |
| Serum protein electrophoresis | A laboratory technique that separates blood proteins into bands by size and charge, revealing an abnormal spike. |
| CRAB | A memory aid for the four types of organ damage in active myeloma: calcium, renal, anemia, bone. |
| MGUS | Monoclonal gammopathy of undetermined significance. A small M protein with no organ damage and no treatment needed. |
| Smoldering myeloma | An intermediate stage with more abnormal plasma cells than MGUS but still no organ damage. |
| Hypercalcemia | A calcium level in blood above the normal range, which in myeloma reflects bone being broken down. |
| Bone marrow biopsy | A sample of marrow taken from the hip bone to count plasma cells and test their genetics. |
| Measurable residual disease | Very small numbers of remaining myeloma cells that only highly sensitive laboratory methods can detect. |
Frequently asked questions
What is often the first sign of multiple myeloma?
There is no single first sign. In many people the earliest clue is an abnormal laboratory value found for another reason, such as a low red cell count, a high total protein, a raised calcium level, or a creatinine result that has drifted upward. When a symptom comes first, it is most often persistent bone pain in the back, ribs or hips that does not behave like ordinary muscular pain. Because these findings have many other explanations, the sequence is always the same: your doctor puts the result in context, then decides whether protein studies are warranted.
Can a routine blood test detect multiple myeloma?
A routine panel can raise suspicion, but it cannot confirm the diagnosis. A standard chemistry panel may show a high total protein, a low albumin, a raised calcium level or reduced kidney function, and a blood count may show anemia. Confirming a plasma cell disorder requires specific protein studies, namely serum protein electrophoresis, immunofixation and free light chain measurement, usually followed by a bone marrow biopsy and imaging. Those additional tests are ordered by a physician when the overall picture justifies them.
Are multiple myeloma symptoms different in women?
The disease behaves in broadly the same way in men and women, and the CRAB pattern is the same. Myeloma is diagnosed somewhat more often in men, and it is more common in Black adults than in white adults. What differs in practice is how symptoms get interpreted: back pain and fatigue in a postmenopausal woman may first be attributed to osteoporosis or to menopause, which can delay the protein studies. Mentioning that the pain is persistent, disturbs sleep, or came after a minor incident helps direct the assessment.
Is multiple myeloma hereditary?
Myeloma is not an inherited disease in the way that some conditions are passed directly from parent to child, and there is no routine genetic test for family members. Having a parent or sibling with myeloma or with MGUS does raise your own risk by a modest amount, so it is useful information to give your doctor. The genetic changes that drive the disease are acquired during life inside a single plasma cell, not present in every cell of the body from birth.
Does myeloma bone pain come and go?
It can, especially at the beginning. Pain from a weakened bone often worsens with movement and eases with rest, so it may seem to fluctuate for weeks. What distinguishes it from ordinary mechanical back pain is that it tends to persist over time, may wake you at night, and can appear suddenly and severely if a small fracture occurs. Pain that changes character, becomes constant, or follows a minor knock should be assessed rather than managed with over-the-counter painkillers alone.
Can multiple myeloma be cured?
Myeloma is generally described as treatable rather than curable, and most people go through periods of remission and relapse. That framing has become more hopeful over the last two decades: combination therapy, transplant and newer immune treatments have lengthened survival considerably, and a minority of people remain free of detectable disease for many years. Outcomes vary widely depending on stage, genetics, kidney function and general health, so the only meaningful estimate is the one your hematologist gives you for your own situation.
Sources
- Mayo Clinic — Multiple myeloma: symptoms and causes, 2025 — mayoclinic.org
- MedlinePlus, National Library of Medicine — Multiple myeloma, 2025 — medlineplus.gov
- Cleveland Clinic — Multiple myeloma: diagnosis, staging and treatment, 2025 — my.clevelandclinic.org
- Rajkumar SV — Multiple myeloma: 2024 update on diagnosis, risk-stratification, and management — American Journal of Hematology, 2024 — doi.org/10.1002/ajh.27422
- Liu Y, Parks AL — Diagnosis and management of monoclonal gammopathy of undetermined significance: a review — JAMA Internal Medicine, 2025 — doi.org/10.1001/jamainternmed.2024.8124
- Einarsson Long T, Rognvaldsson S, Thorsteinsdottir S, et al. — New definition of light chain monoclonal gammopathy of undetermined significance — JAMA Oncology, 2025 — doi.org/10.1001/jamaoncol.2025.1285
- Zanwar S, Kumar S, Rajkumar SV — Diagnosis, risk stratification and management of smouldering multiple myeloma — Nature Reviews Clinical Oncology, 2026 — doi.org/10.1038/s41571-026-01119-0
- Facon T, Dimopoulos MA, Leleu XP, et al. — Isatuximab, bortezomib, lenalidomide, and dexamethasone for multiple myeloma — New England Journal of Medicine, 2024 — doi.org/10.1056/NEJMoa2400712
- Usmani SZ, Facon T, Hungria V, et al. — Daratumumab plus bortezomib, lenalidomide and dexamethasone for transplant-ineligible or transplant-deferred newly diagnosed multiple myeloma: the randomized phase 3 CEPHEUS trial — Nature Medicine, 2025 — doi.org/10.1038/s41591-024-03485-7
- Perrot A, Moreau P, Avet-Loiseau H, et al. — Measurable residual disease-guided therapy in newly diagnosed myeloma — New England Journal of Medicine, 2025 — doi.org/10.1056/NEJMoa2505133
- Bridoux F, Leung N, Nasr SH, et al. — Kidney disease in multiple myeloma — La Presse Medicale, 2024 — doi.org/10.1016/j.lpm.2024.104264
Further reading
- Readers comparing blood cancers often review the guide to leukemia symptoms and treatment.
- Another cancer of the immune system is covered in the article explaining lymphoma symptoms and treatment options.
- Work-ups for unexplained fatigue frequently include the erythrocyte sedimentation rate.
- Protein studies are easier to follow once you understand the albumin blood test.
- Marrow function is also reflected by the platelet count.
Understand your lab results with BloodSense
Plasma cell disorders are followed through numbers on a page: total protein, albumin, calcium, creatinine, hemoglobin and free light chains, measured again and again over time. Seeing what each value represents, and whether it is moving, makes those appointments far less bewildering. BloodSense reads your blood, urine and stool reports and explains them in plain language. It helps you understand your results; it does not diagnose, and it does not replace your doctor.
