Low Blood Pressure in Multiple Myeloma: What It Means and When to Worry

Low blood pressure (hypotension) in someone with multiple myeloma can have several potential causes, ranging from the disease itself (like anemia or blood chemistry changes) to side effects from treatment (such as certain chemotherapy drugs). It often can be managed, but it’s worth paying attention, especially if you feel dizzy, light‑headed, weak, or have fainting episodes.

Why myeloma can contribute to low blood pressure

• Anemia and fatigue: Myeloma can crowd out normal red blood cell production, leading to anemia, which may make you feel weak, dizzy, or light‑headed and can contribute to low blood pressure symptoms. ^[1]
• High calcium and “thick blood” changes: Myeloma can raise blood calcium (hypercalcemia) and increase blood protein levels, both of which affect how you feel (confusion, dizziness) and may relate to fluid shifts and dehydration that lower blood pressure. ^{[2] [3]}
• Kidney involvement: Myeloma proteins can damage the kidneys, which can disturb fluid and salt balance, sometimes lowering blood pressure or making you more sensitive to dehydration. ^[4]

Treatment-related causes to consider

Some anti-myeloma therapies can lower blood pressure or make you feel dizzy, especially around infusion or injection days.

• Bortezomib (Velcade): Hypotension (including orthostatic, or “standing up” low blood pressure) occurs in a notable minority of patients; most cases are mild to moderate, but severe cases can happen and occasionally lead to treatment discontinuation. ^[5]
• Monoclonal antibodies and chemo combinations: Certain regimens used in blood cancers can be associated with low blood pressure during or after treatment, and teams usually monitor blood pressure regularly and advise hydration and slow position changes. ^[6]

How to recognize it

• Common symptoms: Dizziness, light‑headedness, blurry vision, fatigue, nausea, or fainting often worse when standing up quickly. If you notice these after treatment days or during periods of poor intake, dehydration may be part of the picture. ^[7]
• Related signs: Low urine output, fast heartbeat, or headaches can accompany dehydration-linked hypotension. ^[7]

When you should be concerned

• Urgent symptoms: Fainting, chest pain, shortness of breath, confusion, or persistent severe dizziness warrant urgent medical review. Sudden or severe changes can signal dehydration, significant anemia, heart rhythm issues, or treatment side effects that need prompt attention. ^[7]
• Persistent or worsening: If low blood pressure symptoms continue despite fluids and rest, or if they recur around treatment cycles, let your oncology team know so they can adjust medications and check labs (blood counts, calcium, kidney function). ^{[4] [1]}

Practical steps you can take

• Hydration and salt (if appropriate): Drink fluids regularly unless your care team has fluid restrictions; small amounts of salt may help some people, but always check with your clinician if you have kidney or heart concerns. ^[6]
• Rise slowly: Move from lying to sitting to standing in stages to reduce dizziness and prevent falls. ^[6]
• Track your blood pressure: Home readings (morning and evening, sitting and then standing) can help your team see patterns, especially around treatment days. ^[6]
• Review medications: Bring a full list some pain meds, anti‑nausea drugs, and blood pressure medicines can lower blood pressure further and might need adjustments on treatment days. ^[6]
• Nausea control: If treatment causes vomiting, work with your team to control nausea and maintain fluids to prevent dehydration-related drops in blood pressure. ^[7]

What your care team may check

• Blood counts: To assess anemia related to myeloma activity. ^[1]
• Chemistry panels: Calcium levels, kidney function, and proteins to gauge dehydration risk and myeloma effects. ^{[2] [4]}
• Treatment timing and side effects: They may adjust the schedule or pre‑medications and monitor blood pressure during infusions or injections, especially with bortezomib or antibody therapies. ^{[5] [6]}

Bottom line

Low blood pressure in multiple myeloma can be due to the disease (anemia, kidney effects, changes in calcium and proteins), dehydration, or treatment side effects. It’s common to experience mild, manageable episodes, but persistent, severe, or symptomatic low blood pressure deserves prompt evaluation to prevent falls and to rule out complications. ^{[2] [4] [1] [5] [7] [6]}