Bone pain is the most common first sign of multiple myeloma. Roughly 70% of patients have bone pain when they’re initially diagnosed, making it the single most frequent reason people seek medical attention before learning they have this blood cancer. The pain most often shows up in the spine, hips, chest, or skull, and it tends to feel like a deep, persistent ache that worsens with movement.
Why Bone Pain Comes First
Multiple myeloma is a cancer of plasma cells, a type of white blood cell that normally produces antibodies. When these cells grow out of control, they accumulate in the bone marrow and interfere with the normal cycle of bone maintenance. Healthy bone is constantly being broken down and rebuilt. Myeloma cells tip that balance heavily toward destruction by activating the cells responsible for breaking bone down while suppressing the cells that build it back up.
This process does two things. It weakens the bone itself, creating holes called lytic lesions, and it releases growth factors from the damaged bone matrix that actually feed the cancer cells further. The result is a cycle: tumor growth drives bone destruction, and bone destruction drives more tumor growth. That’s why the pain often starts gradually and gets worse over time rather than appearing suddenly.
In many cases, the first bone pain is in the lower back, because the spine is rich in bone marrow and bears significant mechanical load. Some people initially assume it’s a pulled muscle or age-related back pain, which can delay diagnosis. Pain in the ribs, hips, or pelvis is also common early on. If the bones of the spine weaken enough to collapse, a compression fracture can cause sudden, severe back pain and potentially press on spinal nerves.
Fatigue and Weakness as Early Signs
After bone pain, the next most common early symptom is a general feeling of weakness, fatigue, or being unwell. This is almost always caused by anemia. Myeloma cells crowd out the normal blood-producing cells in the bone marrow, leading to a drop in red blood cells. You might notice feeling unusually tired doing things that didn’t used to exhaust you, or you might feel short of breath climbing stairs. Because fatigue is so vague and common, it’s easy to attribute to stress, poor sleep, or aging, which is another reason myeloma often goes undiagnosed for months.
The CRAB Symptoms
Doctors use the acronym CRAB to describe the four hallmark signs that signal active multiple myeloma requiring treatment. Each letter represents organ damage caused by the cancer:
- Calcium elevation. Bone destruction releases calcium into the bloodstream. High calcium levels can cause excessive thirst, frequent urination, constipation, nausea, and mental confusion or fogginess. Some people describe feeling “off” mentally before they know anything is wrong.
- Renal (kidney) problems. Abnormal proteins produced by myeloma cells can clog and damage the kidneys. Early signs include swelling in the legs, decreased urine output, or unexplained changes in how often you urinate.
- Anemia. As described above, low red blood cell counts cause fatigue, weakness, and pallor.
- Bone disease. Lytic lesions, fractures, or generalized bone thinning. A diagnosis requires at least one area of bone destruction measuring 5 mm or larger on imaging.
Having even one of these CRAB features, combined with abnormal plasma cells in the bone marrow, is enough to diagnose active myeloma. Not every patient experiences all four, and they don’t necessarily appear in any set order. But bone pain and fatigue are by far the most likely to show up first.
Fractures From Minor Injuries
Some people discover they have myeloma not through gradual pain, but through a bone fracture that happens with surprisingly little force. A rib might break from a cough. A hip might fracture from a minor stumble. These pathological fractures happen because the bone has already been silently weakened by lytic lesions. In some cases, the fracture itself is the event that triggers imaging and bloodwork, leading to diagnosis.
Signs That Often Get Overlooked
Beyond the obvious bone pain and fatigue, myeloma can cause subtler problems that are easy to dismiss. Frequent infections are one: because myeloma disrupts normal antibody production, your immune system becomes less effective. If you’re getting sick more often than usual, or infections seem to linger longer, that can be a clue. Unexplained weight loss, numbness or tingling in the hands and feet, and persistent nausea can also occur early, though they’re less common as the very first symptom.
High calcium levels deserve special attention because the symptoms mimic many other conditions. Feeling confused, extremely thirsty, or constipated without an obvious explanation can seem unrelated to cancer, but in the context of myeloma, these signs point to calcium leaching from damaged bones into the bloodstream.
Precursor Conditions Before Myeloma
Multiple myeloma doesn’t always appear out of nowhere. It almost always develops from a precursor condition called MGUS (monoclonal gammopathy of undetermined significance), where abnormal plasma cells produce a small amount of abnormal protein but haven’t yet caused any damage. MGUS itself causes no symptoms. It’s typically discovered incidentally through blood tests done for other reasons.
Between MGUS and active myeloma sits a middle stage called smoldering myeloma, where the abnormal protein levels are higher and more plasma cells are present in the bone marrow, but there’s still no organ damage. The distinction matters: in MGUS, the abnormal protein level is typically under 3 g/dL and bone marrow contains fewer than 10% abnormal plasma cells. Active myeloma requires 10% or more abnormal plasma cells plus at least one sign of organ damage.
People diagnosed with MGUS progress to active myeloma at a rate of about 1% per year, so most never develop cancer. But understanding this progression helps explain why myeloma’s first true symptom, usually bone pain, can seem sudden even though the underlying condition has been quietly evolving.
How Myeloma Is Detected
When bone pain or other symptoms raise suspicion, the diagnostic workup involves several types of tests. Blood tests look for abnormal proteins (called M-proteins) produced by cancerous plasma cells. In most myeloma patients, this protein level exceeds 3 g/dL, though about one in five patients has levels below 1 g/dL, which can make detection trickier. A complete blood count checks for anemia, and a metabolic panel measures calcium levels and kidney function.
Urine tests screen for abnormal proteins that the kidneys are filtering out. Imaging, preferably a PET/CT scan or low-dose CT, looks for lytic bone lesions. A bone marrow biopsy confirms the percentage of abnormal plasma cells and provides genetic information that helps determine how aggressive the cancer is likely to be.
Certain chromosomal abnormalities found during biopsy analysis indicate higher-risk disease. Having two or more of these genetic changes classifies the myeloma as very high risk, which influences treatment decisions. This genetic profiling has become a standard part of diagnosis in current guidelines.
What the Timeline Looks Like
The gap between when symptoms start and when myeloma is diagnosed can range from weeks to many months. Back pain is so common in the general population that neither patients nor doctors immediately think of cancer. Fatigue is similarly nonspecific. The combination of persistent, unexplained bone pain that doesn’t respond to typical treatments, worsening fatigue, and abnormal routine blood work (particularly low hemoglobin or elevated calcium) is what usually prompts deeper investigation. Most patients are over 60 at diagnosis, though it can occur earlier, and the average age when symptoms first appear tends to be in the mid-to-late 60s.