caf·fein·ism 
(kă-fēnĭz′əm, kăfē-, kăfē-ə-)
(kă-fēnĭz′əm, kăfē-, kăfē-ə-)n.
A toxic condition marked by diarrhea, elevated blood pressure, rapid breathing, heart palpitations, and insomnia, caused by excessive ingestion of coffee and other caffeine-containing substances.