Why It Happens

Blood pressure spikes during fasting are often due to stress hormone fluctuations, dehydration, or underlying imbalances. While fasting can benefit blood pressure long-term, short-term spikes may occur.

Increased Cortisol and Adrenaline: Fasting activates stress pathways that can raise blood pressure, especially in the early phases.

Electrolyte Imbalance: Without food, you may lose sodium and potassium, both critical to pressure regulation.

Dehydration: Low fluid intake leads to reduced plasma volume and higher vascular resistance.

Caffeine Use While Fasting: Stimulants on an empty stomach can spike pressure quickly.

Underlying Hypertension: Fasting may expose hidden blood pressure issues by stressing regulatory systems.

How to Manage

Stay Hydrated with Electrolytes: Drink water plus magnesium, potassium, or salt during fasting windows.

Avoid Overexertion While Fasting: Limit intense workouts if you're prone to pressure spikes.

Use Calm Support: Try adaptogens, teas, or meditation to regulate cortisol.

Avoid Fasting if Hypertensive: Check with your provider before using fasting as a tool if pressure is already elevated.

Test and Track: Use wearables or home cuffs to monitor changes throughout your fast.

Fasting can help — but if it raises pressure, the solution may be found in minerals and rhythm.

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References

• CDC – About High Blood Pressure

• American Heart Association – HBP

• NCBI – Understanding BP variability