**Question:** The Most common cause of bleeding from nipple is

A. Galactorrhoea
B. Nipple inversion
C. Trauma or injury
D. Infection

**Correct Answer:** A. Galactorrhoea

**Core Concept:** Galactorrhoea is the medical term for the involuntary discharge of milk from the breasts, typically seen in women. This condition is often caused by hormonal imbalances, particularly when breastfeeding is not present.

**Why the Correct Answer is Right:** Galactorrhoea is the most common cause of bleeding from the nipple due to its association with hormonal imbalances, which can be further categorized into:

1. Primary galactorrhoea: Occurs due to abnormalities in the hypothalamus or pituitary gland, leading to overproduction of prolactin (a hormone responsible for milk production). This can be seen in conditions like pituitary tumors, hyperprolactinemia, or lactotroph adenomas. These hormonal imbalances cause the ejection of milk from the breasts, leading to nipple bleeding.
2. Secondary galactorrhoea: Resulting from abnormalities in the hypothalamic-pituitary-gonadal axis, this may occur due to disorders like polycystic ovary syndrome (PCOS), thyroid disorders, or medications affecting the hypothalamus or pituitary gland.

**Why Each Wrong Option is Incorrect:**

C. Nipple trauma or injury: Trauma to the nipple itself or surrounding tissue would typically cause pain, redness, and swelling rather than the involuntary discharge of milk.

D. Infection: Bleeding from a nipple due to infection is usually associated with local signs and symptoms, such as redness, swelling, pain, and purulent discharge. Infection is not a primary cause of involuntary milk discharge from the nipple.

**Clinical Pearl:** It is essential for medical students and practitioners to differentiate between primary and secondary galactorrhoea, as the underlying causes may require specific treatment approaches. Primary galactorrhoea is usually managed with dopamine agonists (e.g., cabergoline), while secondary galactorrhoea requires addressing the underlying disorder (e.g., treating thyroid dysfunction or adjusting medications).