German Chancellor Angela Merkel appeared unsteady and was visibly shaking yesterday as she greeted the new Ukrainian leader in the hot sun in Berlin, saying later that she clearly hadn't drunk enough water.
Merkel's whole body visibly shook and she pursed her lips as she tried to contain the situation as she stood with Ukrainian President Volodymyr Zelenskiy in the 28C heat while a military band played their national anthems outside the chancellery.
But following the anthems, Merkel seemed better, walking quickly along the red carpet with Zelenskiy into the building, pausing to greet the military band and take a salute.
About an hour later, following their meeting, Merkel told reporters at a joint news conference that they had discussed bilateral issues and the Minsk peace process during Zelenskiy's first visit to the German capital as president.
Merkel, who turns 65 next month, smiled broadly after a reporter asked whether her shaking was cause for concern. She replied that she was fine.
"Since then I've drunk at least three glasses of water, which I apparently needed, and now I'm doing very well," she said.
She laughed and gave Zelenskiy a smile when he assured reporters the chancellor had been secure at his side.
"She was totally safe," he said.
The dpa news agency reported that this was not the first time Merkel has been seen shaking under similar circumstances in the hot sun. It did not give a date for that incident, but said it was also ascribed to Merkel not drinking enough water.
And in 2014, Merkel postponed a television interview at the last minute after reported weakness, but her spokesman said at the time she was able to carry it out later after eating and drinking something.
It is not publicly known if Merkel, who has led Germany since 2005, has any health problems. German privacy laws are very strict on that type of information.
Can dehydration give you the shakes?
Angela Merkel said she was just dehydrated after footage emerged of her visibly trembling at an official ceremony.
However, the British NHS does not list shivering or tremors as a known symptom of dehydration - when the body loses more fluid than it takes in.
Instead, symptoms usually include: feeling thirsty, having dark urine, feeling dizzy, tired or light-headed, or having a dry mouth.
Dr Sarah Brewer, a GP and medical director of Healthspan, said: "In general, several different things can contribute to shaking, such as shivering with cold."
She told MailOnline it could be caused by having an over-active thyroid, a condition which the NHS says is 10 times more likely to strike women than men.
Dr Brewer added that shaking could be a side effect of some medication. The US National Library of Medicine lists 17 different drugs that can cause the shakes, including caffeine, antibiotics, antidepressants, alcohol or nicotine.
Shaking, which is uncontrollable, can also be a sign of low blood sugar - a serious complication often seen in diabetic patients.
Or, it can be caused by a fever, fear, stress or a medical condition called essential tremor. The neurological disease strikes up to four per cent of people over the age of 40 in the UK, data suggests. It is unclear how common it is in Germany.
Peter Garrard, a professor at St George's, University of London, said Merkel's symptoms "seem to fit with a diagnosis of orthostatic tremor".
The rare disorder tends to strike people in their 60s. Patients can suffer shaking in their legs when they stand, which can spread to their upper body. It often stops when they move.
Professor Garrard told MailOnline: "The apparent severity [of Mrs Merkel's shakes] is probably amplified by the hang of Mrs Merkel's loose fitting tunic and trousers.
"It typically goes away when the sufferer hangs on to or leans against something, which may explain why she does not appear tremulous when she is standing behind a lectern."
Dr Philippa Kaye, a London-based GP, told MailOnline: "Importantly it [Mrs Merkel's shakes] seemed to stop when she started walking."
Merkel has never spoken of any medical ailment she has.
Ley Sander, a professor of neurology at University College London told MailOnline the shakes Merkel had was definitely 'not a sign' of Parkinson's - a condition often associated with tremors.
- AP, with Daily Mail