 Each ascent and descent increases the risk of decompression sickness if there are any bubbles already in the diver's tissues.The increase in risk depends on the ascent rate, magnitude and duration of the upwards excursion, the saturation levels of the tissues, and to some extent the time spent after returning to depth.Accurate assessment of the increase of risk is not currently (2016) possible, but some dive computers make an adjustment to the decompression requirement based on violations of recommended maximum ascent rate as an attempt to compensate.