To prevent weed headaches, you can: Stay hydrated before, during and after consuming weed: Dehydration can trigger headaches and worsen the effects of weed. Choose strains that are low in THC and high in CBD: THC can cause blood pressure changes and anxiety, which can lead to headaches. CBD has anti-inflammatory and pain-relieving properties that can help with headaches. Avoid mixing weed with alcohol, tobacco or other drugs: These substances can interact with weed and increase the risk of headaches and other side effects. Take a break from weed if you experience frequent or severe headaches: Weed can cause rebound headaches if used too often or in high doses. Taking a break can help your body reset and recover.