What are the downsides of nicotine?

As a curious observer of health and lifestyle choices, I'm often intrigued by the potential risks of various substances. In the case of nicotine, it's a chemical compound commonly found in tobacco products, and I'm wondering about its downsides. Is there a significant risk of addiction associated with nicotine use? What are the potential effects on heart health, such as an increased risk of heart disease? Are there any long-term effects on the respiratory system, like an increased risk of lung cancer? Additionally, does nicotine affect cognitive function, such as memory and concentration? I'd appreciate a concise yet comprehensive overview of the potential drawbacks of nicotine consumption.