According to WHO, within 20 minutes of quitting, blood pressure and heart rate drop, and within two to 12 weeks, lung function and circulation improve

When symptoms do appear, they may include: Early Warning Signs (Don't Ignore): Non-healing sore or ulcer: A sore on the lip, tongue, or inside the cheek that does not heal within 2-3 weeks White or red patch: A persistent white (leukoplakia) or red (erythroplakia) patch anywhere in the mouth Lump or thickening: A rough spot, crust, or small lump on the lip or inside the mouth Numbness or pain: Unexplained pain, tenderness, or numbness in any area of the mouth, face, or neck Progressive Symptoms (As Cancer Grows): Difficulty chewing or swallowing (dysphagia): Food may get stuck, or swallowing may become painful Difficulty speaking or moving the tongue or jaw Loose teeth or ill-fitting dentures (not explained by other dental issues) A lump in the neck: Enlarged lymph nodes indicating possible spread Ear pain (referred pain from oral tumor) Unexplained weight loss Bleeding from the mouth not caused by injury Also read: How to take care of Teeth with Cavities

Withdrawal from quitting tobacco can be severe, making cessation particularly challenging due to nicotines rapid onset and strong cravings
You are not willing to get rid of your old ways
Streptococcus Sanguinis Biofilm Formation & Interaction With Oral Pathogens