Breath-Hold Divers Get Decompression Sickness Too
Decompression sickness, or the bends, is caused by nitrogen bubbles forming in the body. During ascent the pressure reduces and the volume of gas in the blood and tissues increases. If the ascent is too fast the bubbles may reach a dangerous size and prevent blood flow or damage tissues.
Normally associated with SCUBA diving, decompression sickness (DCS) is also be a risk for repetitive breath-hold diving. This was put forward as early as 1965 but is still not widely acknowledged.
A new study published in the Research in Sports Medicine journal compared four groups of breath-hold divers: (1) Japanese and Korean amas and other divers from the Pacific area, (2) instructors at naval training facilities, (3) spear fishers, and (4) .dive athletes.
The researchers report some 90 cases in which DCS occurred after repetitive breath-hold dives. Because the risk of suffering from DCS increases depending on depth, bottom time, rate of ascent and duration of surface intervals, some approaches to assess the risks are presented. Regrettably, none of these approaches is widely accepted.