Dr Helmi is concerned about Mrs Chandler's state of mind
Paul and Rachel Chandler have spent 100 days as captives of Somali pirates - but how much longer can the couple, originally from Tunbridge Wells in Kent, survive? The BBC's Peter Greste in Nairobi looks at their situation.
Mrs Chandler is clearly exhausted. Gaunt, anxious and pale, she appeared in a video by a freelance Somali journalist who saw her with a doctor.
From a heavily guarded hideout in a tent, she pleaded for help: "We have not much time left and are being badly treated."
The couple are being held in extremely difficult conditions.
According to a French news agency AFP, the two are being held in separate locations - presumably to discourage any rescue attempt.
The couple say they need urgent help
Mrs Chandler is living under a shelter constructed with orange netting, a tarpaulin and a few blankets.
The doctor, Abdi Mohamed Helmi, said she appeared to be struggling with the local diet - most likely rice or maize meal with little else in the way of protein or fresh vegetables - and poor quality water.
But more worryingly, Dr Helmi said the 56-year-old also appeared to be suffering from psychological stress.
"She's very confused," the doctor said. "She's always asking about her husband - 'Where's my husband, where's my husband?' - and she seems completely disorientated."
The doctor's verdict on 60-year-old Mr Chandler was that he was in slightly better health but with a bad cough and a mild fever.
The health of the Chandlers could well be the key issue in this process.
Dr Helmi said the pirates did not seem to be beating their captives, but equally they did not seem to care about making them comfortable.
"They are being held under trees, in very hot conditions - 39C.
"You cannot imagine the food they are eating and the water they are drinking - very bad."
Even so, there are no reported cases of pirates killing captives - either deliberately or through neglect.
A ransom was reportedly paid for Amanda Lindhout and Nigel Brennan
The pirates are in business for money alone, so it would be in their interests to make sure their hostages survive. But this could be a long ordeal.
In November last year, Somali gunmen released two journalists - Australian photographer Nigel Brennan and Canadian reporter Amanda Lindhout - after 15 months, and a ransom reported to be in excess of $1m (£600,000).
The Canadian and Australian governments had refused to discuss the ransom demand, and it was only when Mr Brennan's family raised the money with the help of some wealthy businessmen that the journalists' release could finally be negotiated.
The British Foreign Office has adopted the same policy as the Canadians and Australians.
It issued a statement after an anti-piracy maritime group insisted it should be allowed to negotiate a payment for the Chandlers, saying concessions "only encourage future kidnaps".
So, if the Chandlers' family want Paul and Rachel free, they will have to work through their own private channels.
Somali sources close to the pirates say negotiations "are under way", although they refused to say what exactly was being discussed.
But the experience of other shipping companies suggests the longer the process continues, the more expensive it becomes.
There are reports of pirates delivering itemised invoices, detailing costs such as fuel for their boats, food for the captives and gunmen, ammunition, satellite telephone calls and so on.
The gunmen holding the Chandlers will be running up similar expenses, and security analysts say they will expect to turn a profit.
The Chandlers video statements - and the visit by the doctor - are almost certainly a part of the captors' strategy to put pressure on their family to find the money.
The gunmen are in total control, and nobody gets in to see the hostages, or no message gets out, that they do not think will help their cause.
There seems little doubt the Chandlers are suffering, but just as doubtless is the fact it suits the pirates for the world to know it.