One cause of bleeding mouth is from clenching or grinding also called bruxism. This generally occurs when you are sleeping. The constant pressure and clenching of the teeth can affect the gums negatively and therefore causing the gums (or gingiva) to bleed.

How do you sleep with bleeding gums?

By keeping your head slightly higher than the rest of your body, this will slow down the blood circulation which will not only help reduce the swelling and bleeding in your mouth, it will give your gums time to heal adequately. Additionally, there can be some throbbing pain associated with recovery from dental surgery.

Why is there blood in my mouth when I wake up?

Blood in your mouth is often a result of trauma to your mouth or throat, such as chewing or swallowing something sharp. It could also be caused by mouth sores, gum disease, or even vigorous flossing and brushing of your teeth. If you're coughing up blood, it might appear that your throat is bleeding.