The exact cause of sudden infant death syndrome (SIDS) is still unknown. However, there are several factors that have been associated with an increased risk. These include abnormalities in the brain that control breathing and arousal from sleep, respiratory infections, exposure to tobacco smoke before and after birth, overheating during sleep, and sleeping on the stomach or side. It is believed that SIDS occurs when multiple risk factors coincide, leading to a failure in the infant's ability to wake up when faced with a life-threatening situation during sleep. To reduce the risk of SIDS, it is recommended to place infants on their back to sleep, use a firm mattress in a safety-approved crib, avoid overheating the baby, and create a smoke-free environment. Regular prenatal care and breastfeeding have also been found to have a protective effect against SIDS.