Overdosing medicine will certainly lead to serious illness.
It will certainly lead to serious illness to overdose medicine.
多くの薬を飲み過ぎると、かえって重大な病気にかかります。
単純に表現してみました。
多くの薬の飲みすぎ overdose medicine
（強い）推量 助動詞 will
～につながる lead to
確かに certainly
重大な病気 serious illness
Overdosing medicine will certainly lead to serious illness.
仮主語を使って、
It will certainly lead to serious illness to overdose medicine.
日本 
