Angela Merkel has insisted she is in good health after experiencing a third bout of shaking in as many weeks at a public event in Berlin.

The German chancellor was seen trembling during military honours for Finland’s prime minister, Antti Rinne, in the forecourt of her chancellery on Wednesday morning.

The bout of shaking was said to be less intense than in the previous two instances, and stopped when Merkel moved her body.

Play Video 0:25 Angela Merkel seen shaking for the third time in a month – video

“I am doing fine and you should not worry,” she said in a press conference after the meeting, adding that she was going through a phase of psychologically “processing” her first shaking episode last month.

Angela Merkel seen shaking for second time in just over a week Read more

Merkel’s public bouts of shaking have fuelled speculation about her health. On 18 June, she was seen involuntarily shaking during military honours for the visiting Ukrainian president, Volodymyr Zelenskiy. She later appeared to blame dehydration, saying she felt better after drinking some water.

She was seen going through a similar bout just a week later, during an appointment with the German president, Frank-Walter Steinmeier, at Bellevue Palace in Berlin.

Citing sources in government circles, the newspaper Stuttgarter Nachrichten said at the time that Merkel’s trembling had been triggered by the memory of the previous shaking bout, calling it a “psychological process”.

“I have already said that I am going through a phase of processing the recent military honours with President Zelenskiy,” the chancellor said on Wednesday. “This appears not to be quite finished yet, but I am making progress and will have to live with it for a while.”

Play Video 0:44 Angela Merkel shakes during national anthem, blaming dehydration – video

She was also seen shaking during military honours in humid conditions in Mexico City on a visit in 2017.

The 64-year-old’s work ethic and stamina during late-night negotiations has become the stuff of legend since she became chancellor in 2005. She once prided herself on having a “camel-like” capacity to store up sleep.

Partially as a result of this reputation, the three televised instances of shaking have fuelled speculation about whether her intense schedule is beginning to take its toll.

While coverage of the first shaking bout in German media was initially restrained, newspaper columns have since been filled with medical experts speculating about the cause.

The German Green party co-leader Annalena Baerbock had suggested Merkel’s shaking episodes could be connected to the climate crisis, saying at a press conference that “regarding the hot temperatures, we can see from the chancellor it is clear that this summer climate has health consequences”. She later apologised for her comments.

“There is little information available beyond what has been stated by Angela Merkel, so it’s impossible to know what might be the cause,” said Peter Roberts, emeritus professor of pharmacology at the University of Bristol.

“An initial effect caused by dehydration, followed by anxiety that it may occur again, might even be the cause. The stress response is a basic survival mechanism and kicks in as soon as a threat is perceived, including fear that something may happen”.

In the absence of any underlying pathology, Roberts said uncontrollable shaking could be the result of a normal stress response. “The problem with the response is that our bodies behave in this way in response to both real and feared threats. Indeed, the fear that your body is going to start behaving in a seemingly abnormal way may precipitate that very response.”