Nobody wants them, but they're a fact of life for a round-the-world sailor.
With their bodies pushed to the extreme as they encounter sleep deprivation, temperatures ranging from below zero to in excess of 40C, and dangerous conditions including 15m waves and hurricane-force winds, injury and illness are part and parcel of the Volvo Ocean Race.
Team New Zealand's medical director, Paul Wilson, says ensuring sailors are at their optimum health and fitness before they take to the sea is critical to their bodies' ability to survive without any injury or illness.
Wilson and his medical team spent nearly a year working with the sailors to ensure they were in peak condition to tackle the race, which requires unimaginable stamina and fortitude.
Since then he and his wife, Dr Donna Wilson, have kept a constant watch on the sailors' health, checking their vital signs, blood results, weight, fat and muscle composition immediately after they arrive at the end of each leg.
On any given leg the sailors can lose between 2kg and 8kg of body weight - most of it muscle wastage.
During the longer stopovers Wilson says they can generally get the sailors back up to 90 per cent of their weight before they started the leg, but with the cumulative effect of each leg they continue to waste away.
"We try and stop the slide and try and turn it around a little bit. During a two and a half to three-week stopover we can actually do that.
"The first week is about rest and recovery and the second week is about building their strength and getting their weight up again.
"On a stopover like this [where there is just one week's turnaround], we haven't got a chance - by the time I get them in Brazil they're going to be skinny little rats."
During the 2008-09 race, more than 530 incidents of injury and illness were reported during medical reviews.
Penny Gough, the medical co-ordinator for the Volvo Ocean Race, said the most common illnesses were skin infections and sores with 67 incidents, followed by 54 cases of "gunwale bum" - apparently a painful, pimply condition caused by spending too much time in damp gear. If you're a bit squeamish it would probably pay not to Google this condition - just take the sailors' word when they say it's not any fun.
The most common injuries involved backs with 44 incidents, followed by wrist or forearm with 43, knees with 35 and elbow with 33.
After a couple of largely incident-free legs, Team New Zealand had a run of injuries in leg four.
Tony Rae, who also doubles as Camper's onboard medic, fractured two ribs 10 days into the leg from China to Auckland after being washed into the back pedestal in heavy seas, while bowman Daryl Wislang dislocated his finger in the tense final stages of the leg as the team rounded North Head.
Rae, who at 50 is the oldest sailor in the six-boat fleet, plans to continue in the race, and has been given the all-clear to take on the gruelling Southern Ocean leg to Brazil with rib damage.
"Ribs are annoying, they don't tend to go away but I've hopefully got myself to a point where I'm ready to go out there again," he said.
Wilson acknowledged it was risky to send an injured sailor back out to the ocean - particularly the 6705-nautical-mile haul to Brazil, which is considered the most dangerous leg in the race.
"It's a risk, there's no doubt about it, but we're comfortable with the risk."