A person usually visits a clinic or doctor’s office to find out their blood type. There, a doctor or nurse draws a blood sample and sends it to a lab for testing.

However, there are ways of determining blood type at home.

By drawing blood

A person can identify their blood type at home using a rapid blood typing kit.

Using the kit requires a person to prick a finger with a needle. The kit comes with a card that contains chemicals known as reagents. These test for the presence of antibodies and the Rh factor.

When one or more of the blood type antibodies or the Rh factor is present in the blood sample, the test produces a “clumping” of the blood. Typically, if clumping does not occur, the person’s blood type is O-negative.

Without drawing blood

A person may be able to use a saliva sample to test for their blood type. Around 80%Trusted Source of people produce the relevant antigens in their saliva.

According to 2018 researchTrusted Source, if a person secretes these antigens in their saliva, a dried saliva sample can reliably indicate their blood type.

However, it is important to note that not everyone secretes these antigens, and this method does not necessarily indicate the presence or absence of the Rh factor.