The blockade just recently started, but the problems in Yemen have been going on for months. From a Reuters story posted today.....
After two years of civil war, Yemen has 7 million people on the brink of famine and has had 900,000 suspected cholera cases in the past six months.
Much of the problems in Yemen can be attributed to the Houthis and alliance with Iran. I hate to be put in the position of defending the Saudis, but they're not the cause of famine and disease in Yemen.