We associate lactation with pregnancy because women produce milk for their babies. This occurs after estrogen and progesterone levels fall. However, lactation can also occur when our body systems have imbalances. The mammary glands begin to produce lactose in a process called galactorrhea.
Overstimulating the nipples can be one cause of this or new medications. However, it can be more serious because tumors also trigger spontaneous lactation. This is something that women should check immediately because it’s not normal. The reason might be innocent but it’s better to know (via Healthline).