Harmful effects caused by alcohol abuse are-
(i) Alcohol generates more energy mostly in the form of heat, but at the same time, it dilates the blood vessels. Consequently the heat generated is rapidly lost. Due to constant dilation, the arterial walls soon become brittle $\&$ rigid. Such a change in the property of blood vessels $\&$ deposition of alcoholic fat affect the working of heart.
(ii) Alcoholism leads to gastric ulcers \& gastritis.
(iii) In chronic alcoholism, the axon of the nerve inflame thus causing neuritis.
(iv) Permanent damage to liver cells occur due to deposition of fats. The liver dries up \& harden (cirrhosis).
Harmful effects caused by drug abuse are-
(i) Excessive doses of drugs may lead to coma \& death due to respiratory failure, heart failure \& cerebral haemorrhage.
(ii) Lack of interest in personal hygiene, withdrawal, isolation, depression, fatigue aggressive \& rebellious behaviour etc.
(iii) Acquire serious infections like AIDS \& hepatitis B, who take drugs intravenously.
(iv) The adverse effects of drugs are manifested in the form of reckless behaviour, vandalism \& violence.