The cause is high blood pressure.
Who the heck is spreading the false rumor that Koichi has high blood pressure?
Fugu has high blood pressure and was told that he must stick to a low-salt diet by a doctor.
Remember blood pressure (血圧)? Well, now the blood pressure is tall... so you have "tall blood pressure." Well that's dumb. Let's call it high blood pressure instead.
This is a jukugo word, which usually means on'yomi readings from the kanji. If you know the readings of your kanji you'll know how to read this as well.