Multiple sclerosis can affect blood pressure in several ways. The disease damages nerve pathways that regulate cardiovascular function, and many MS medications also influence blood pressure as a side effect. Around 42% of people with MS show at least one sign of cardiovascular autonomic dysfunction on testing, making blood pressure irregularities a common but often overlooked part of living with the condition.
How MS Disrupts Blood Pressure Regulation
Your body constantly adjusts blood pressure without you thinking about it. Sensors in your neck and chest detect changes in pressure and send signals through the brainstem and spinal cord, triggering your blood vessels to tighten or relax and your heart to speed up or slow down. MS can interrupt this process at multiple points by damaging the nerve fibers that carry these signals.
Studies have found a direct link between the location of MS lesions and the severity of blood pressure problems. Lesions in the brainstem, particularly in areas that relay information from pressure sensors in the carotid arteries, are strongly associated with impaired blood pressure responses. One study found a significant correlation between the total volume of midbrain lesions and how poorly blood pressure responded to changes in posture. Lesions in the insular cortex and hippocampus, two brain regions involved in autonomic control, have also been linked to a shift toward overactive “fight or flight” signaling to the heart.
Research in MS patients has shown that the baroreceptor reflex, the system responsible for catching and correcting sudden drops in blood pressure, is blunted. In one study comparing 10 MS patients with matched controls, the MS group had a measurably diminished ability to raise blood pressure in response to a drop. This wasn’t limited to heart rate adjustments alone; the blood vessels themselves failed to constrict properly. Spinal cord atrophy, rather than the inflammatory lesions MS is known for, appears to be a key driver of this dysfunction, suggesting that permanent nerve fiber loss plays a larger role than active inflammation.
Orthostatic Hypotension and Dizziness
The most common blood pressure problem in MS is orthostatic hypotension, a drop in blood pressure when you stand up. Between 18% and 24% of middle-aged MS patients meet the clinical threshold for this condition. But the broader picture is even more striking: 50% to 67% of people with MS report symptoms of orthostatic intolerance, including dizziness, lightheadedness, or feeling faint when changing position or standing for long periods.
When blood pressure drops on standing and the body can’t compensate quickly enough, blood flow to the brain temporarily decreases. This can cause anything from mild wooziness to full syncope (fainting). These episodes also contribute to falls, which are already a major concern in MS. Fatigue, one of the most disabling symptoms of MS, may be partly fueled by these repeated dips in brain blood flow throughout the day.
Hypertension and Disease Progression
High blood pressure affects roughly 10% or more of the MS population, with prevalence increasing with age, similar to the general population. Some studies suggest it may be slightly more common in people with MS than in comparable groups without the disease. What makes hypertension particularly important in MS is its relationship to disability progression.
A large study of nearly 2,400 MS patients found that those with hypertension were significantly more likely to reach major disability milestones. Hypertensive patients had a 62% probability of reaching moderate disability compared to 43% for those without high blood pressure. At higher disability levels, the gap persisted: 51% versus 28%, and 17% versus 10%. Interestingly, while hypertensive patients were more likely to become disabled overall, the time between each stage of progression was longer, by roughly 40 to 60 months, compared to non-hypertensive patients who reached the same levels.
The stroke risk is also notable. Among people with MS, having hypertension increases the odds of ischemic stroke by about 3.4 times compared to MS patients without high blood pressure. Even without hypertension, MS patients already carry about 2.7 times the stroke risk of people without MS, making blood pressure management especially consequential.
MS Medications That Affect Blood Pressure
Several disease-modifying therapies used to treat MS can raise or fluctuate blood pressure as a side effect, which means some blood pressure changes in MS aren’t caused by the disease itself but by its treatment.
- Glatiramer acetate: Hypertension was reported in roughly 10% of patients in premarketing studies. Post-marketing reports have included rare cases of hypertensive crisis with serious cardiovascular complications.
- Fingolimod: Typically causes a small, sustained increase of about 3 mmHg systolic and 1 mmHg diastolic, which stabilizes after about six months of treatment.
- Teriflunomide: A slight increase in blood pressure is among the most frequently reported side effects, occurring in 3% to 4% of patients in clinical trials compared to about 2% on placebo.
- Alemtuzumab: Blood pressure changes are listed as a common side effect.
- Natalizumab: Occasional reports of hypertension, typically appearing around two days after infusion.
Intravenous corticosteroids, commonly used to treat MS relapses, can also cause transient blood pressure spikes during or shortly after infusion. If you notice headaches, visual changes, or a pounding sensation during or after treatment for a relapse, your blood pressure may be part of the picture.
Why Monitoring Matters
Blood pressure problems in MS often go unrecognized because the symptoms overlap with the disease itself. Fatigue, dizziness, brain fog, and difficulty with balance are all hallmarks of MS, but they can also be signs that blood pressure isn’t being regulated properly. Someone attributing their lightheadedness entirely to MS may be missing a treatable blood pressure issue.
The National MS Society emphasizes that managing chronic conditions like hypertension is just as important as treating MS directly. Regular blood pressure checks, both at clinic visits and at home, can catch problems that a single office reading might miss. This is especially true for orthostatic hypotension, which by definition only shows up when you change positions. If you feel consistently dizzy when standing, asking for a lying-to-standing blood pressure test can provide useful information.
Standard approaches to blood pressure health apply to people with MS: staying active within your abilities, limiting sodium, maintaining a healthy weight, and addressing sleep quality. For orthostatic hypotension specifically, practical steps like rising slowly from sitting or lying positions, staying well hydrated, and using compression garments can reduce symptoms. When lifestyle measures aren’t enough, blood pressure medications can be adjusted to account for both the MS-related dysregulation and any effects from disease-modifying therapy.