Chronic Fatigue Syndrome and Blood Pressure: The Opposite Relationship
Chronic Fatigue Syndrome (CFS) does not cause high blood pressure—in fact, it is strongly associated with abnormally LOW blood pressure and impaired blood pressure regulation. 1, 2
The Blood Pressure Pattern in CFS
CFS patients consistently demonstrate:
- Significantly lower systolic blood pressure compared to healthy controls (p < 0.0001) 1
- Lower mean arterial blood pressure (p = 0.0002) 1
- Exaggerated diurnal variation in blood pressure patterns (p = 0.009) 1
- Neurally mediated hypotension affecting approximately two-thirds of CFS patients 2, 3
The relationship between fatigue severity and blood pressure is inverse—as fatigue worsens, diurnal blood pressure regulation becomes more abnormal 1. This is the opposite of what occurs with hypertension.
Autonomic Dysfunction Mechanism
The underlying pathophysiology involves autonomic nervous system dysfunction:
- Reduced systolic blood pressure variability in the high-frequency range during both rest and orthostatic stress 4
- Sympathetic predominance of baroreflex heart rate control during orthostatic challenge 4
- Elevated nocturnal blood pressure and heart rate despite overall lower daytime pressures, suggesting disrupted circadian cardiovascular regulation 5
This autonomic dysregulation manifests as orthostatic intolerance rather than sustained hypertension 3.
Clinical Implications
The blood pressure abnormalities in CFS are clinically significant:
- Neurally mediated hypotension occurs in a high proportion of CFS patients and contributes to symptom burden 2, 3
- Treatment targeting hypotension (such as midodrine) has shown benefit in approximately two-thirds of CFS patients in open-label studies 1, 2
- The cardiovascular dysregulation may represent a therapeutic target rather than a complication requiring blood pressure reduction 1
Important Caveat
If a patient with diagnosed CFS presents with elevated blood pressure, consider:
- Separate coexisting hypertension unrelated to CFS, which would require standard hypertension management per guidelines 6
- Nocturnal blood pressure elevation as part of the autonomic dysfunction pattern, which differs from sustained daytime hypertension 5
- Medication effects if the patient is being treated for the hypotensive component of CFS 1
The evidence is unequivocal: CFS is characterized by hypotension and abnormal blood pressure regulation, not hypertension 1, 2, 3.