Smoking is a major health hazard and can cause a variety of serious health problems. Smoking is linked to an increased risk of many diseases and conditions, including cancer (lung, throat, mouth, bladder, kidney, pancreas, and cervical cancers), heart disease, stroke, COPD, and reproductive health problems. It can also worsen existing conditions like asthma, ulcers, and diabetes. Additionally, smoking is particularly dangerous for pregnant women, as it can lead to birth defects, premature labour, and low birth weight. Finally, second hand smoke is an important factor to consider, as it can cause many of the same health risks as smoking, but to a lesser extent.