You may notice blood in your saliva when you spit. Another time you might notice blood in your saliva is when you have a rusty, metallic taste in your mouth.

Let’s take a look at the causes of blood in saliva and how each is treated.

Gingivitis

Gingivitis is a common gum disease (periodontal disease). It presents as swelling and redness of your gums around the base of your teeth. Improper oral hygiene typically causes it.

Treatment usually includes a professional dental cleaning followed by a good oral hygiene routine. Later stages of the condition may require surgical treatment.

Mouth ulcers

Also called canker sores, mouth ulcers are small, painful sores that develop on your gums, inside your lips, and inside your cheeks. The National Health Service says they’re often triggered by:

Treatment for mouth ulcers isn’t typically needed, as they tend to clear on their own. If they grow large or last for more than a couple of weeks, your doctor might recommend prescription mouthwash with dexamethasone or lidocaine.

Over-the-counter (OTC) gels, pastes, or liquids may also help. Options include:

  • hydrogen peroxide
  • benzocaine (Anbesol, Orabase)
  • fluocinonide (Vanos, Lidex) — needs a prescription and it’s for external use only (always check with your dentist or doctor)

You may also consider eating foods containing higher levels of the following vitamins and minerals:

Some cancers, such as lung cancer and esophageal cancer, will cause you to cough up bloody phlegm. This may look like bloody saliva if some blood stays in your mouth, but the blood’s actually not in your saliva.

Cancers that can cause you to have blood in your saliva are:

  • Mouth cancer. This is also called oral cancer or oral cavity cancer. It occurs on the inside of your mouth on your gums, tongue, cheeks, or on the roof or floor of your mouth.
  • Throat cancer. This cancer presents as tumors that develop in your pharynx (throat), larynx (voice box), or tonsils.
  • Leukemia. This cancer affects your blood and bone marrow.

Treatment

Your doctor will discuss treatment options tailored to the stage of the cancer, its specific location, the type of cancer, your current health, and a number of other factors. Treatment might include:

Try to schedule regular appointments with your dentist for cleaning and exams every 6 months. Consider making an immediate appointment if you notice symptoms such as:

You can connect to a dentist in your area using the Healthline FindCare tool.

If you see blood in your saliva and don’t have an explanation, such as aggressive brushing, a canker sore, or biting your tongue, bring it up with your dentist, if possible.

In the meantime, practice good dental hygiene:

  • Brush twice a day.
  • Floss daily.
  • Use a mouthwash with fluoride.