Why was the middle passage so bad

Middle passage was very bad because the mortality was very high and the main cause was the disease, as the "the flux" itself caused by parasites in unsanitary food. Slaves were often kept chained under decks in appalling sanitary conditions, which spread diseases. The stench beneath the decks was sometimes overwhelming. It was said that you could smell a slaving ship for 20 miles downwind and the sharks followed them all the way across the Atlantic, to delight in the slaves often thrown overboard.