Poisonous partnership: How to recognise it and rescue yourself from the toxic dynamic

"A toxic relationship is one that is bad for you and has a negative impact on your life," says clinical psychologist Gemma Cribb. "This negative impact could be decreasing your life satisfaction or disrupting your physical or mental health."

Those effects, she says, will depend on the situation, but there are common themes.

"Generally, a toxic relationship will cause anxiety and/or low mood," she explains. "It will be taking up an undue amount of your thinking. You may want to avoid your friend or partner or feel like you are walking on eggshells. Your sleep can become disturbed, you can lose concentration and feel overly agitated or lethargic.