THC and Blood Pressure: What You Need to Know
THC’s effect on blood pressure is genuinely two-sided — it depends on timing, dose, and whether you’re looking at short-term or long-term use, which is part of why the research on this topic can seem contradictory at first glance.
The short-term effect
In the first few minutes after use, THC typically causes a temporary spike in heart rate and can raise blood pressure briefly. This is followed, often within about 20 minutes, by a drop — sometimes below baseline — as the initial cardiovascular response settles and THC’s vasodilating effects take over.
The long-term picture
With regular use, tolerance develops to some of these cardiovascular effects, and the acute spike-then-drop pattern tends to become less pronounced. Long-term effects on blood pressure specifically are less clearly established than the well-documented acute pattern.
Who should be more cautious
People with existing heart conditions, uncontrolled high blood pressure, or those taking blood pressure medications should talk to a doctor before using cannabis, since the acute changes — however temporary — can interact with existing cardiovascular strain or medication effects.
Orthostatic hypotension
The temporary blood pressure drop after the initial spike can cause dizziness or lightheadedness when standing up quickly, sometimes called orthostatic hypotension. This is a real, reported effect and part of why standing up slowly after using is a reasonable precaution.
FAQ
Can cannabis cause a heart attack?
Cannabis use has been associated with increased cardiovascular risk in some studies, particularly in people with existing heart disease, though the overall risk for healthy individuals appears low. Anyone with cardiovascular risk factors should discuss this with a doctor.
Does CBD affect blood pressure the same way as THC?
CBD has been studied separately and shows some blood-pressure-lowering effects in early research, though it works through different mechanisms than THC.
Written by the CHS SOS Team · Last updated: July 2026
