Breastfeeding provides optimal nutrition and health benefits for infants. It involves the feeding of an infant or young child with breast milk directly from the female breast. The physiological basis of lactation involves four phases: preparation of breasts, synthesis and secretion from breast alveoli, ejection of milk, and maintenance of lactation. Breastfeeding has many advantages for both mother and infant, including improved immunity, nutrition, bonding, and reduced risk of various diseases. Contraindications to breastfeeding include certain medical conditions in the mother or infant. Common problems with breastfeeding include painful or engorged breasts which can often be addressed through proper positioning and feeding techniques.