Answer :
Answer:
"nicotine".
Explanation:
According to my research on the ingredients and side effects of cigarettes the ingredient that complies with all the side effects mentioned is "nicotine". Nicotine is an addicting agent found in cigarettes that can cause headaches, nausea,throat pain, cough, runny nose, heartburn, sweating, and even diarrhea. Since it is addicting the stopping of smoking cigarettes will throw your body into nicotine withdrawal which can cause dizziness, anxiety, depression, or even trouble sleeping.
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