You may begin to bruise easily if you aren’t getting enough iron. That’s because your body needs iron to keep your blood cells healthy. If your blood cells aren’t healthy, your body won’t be able to get the oxygen that it needs to function. This may make your skin more susceptible to bruising.
But there are more causes
https://www.healthline.com/health/random-bruising#nutrient-deficiency
When it’s a sudden change I would have a chat with your GP

I’ve been getting mysterious bruises my whole life. Just clumsy and forgetful in my case.

I would see a doctor to get a check up!

Yes mine was from scratching with ayclic nails on it bruised my legs. Are you on any new meds that could be causing bruising?

PLEASE go to your doctor – could be a number of medical things. Some very serious. I don’t want to frighten you, but urge you to get some blood tests. All the best x

Yes I get it all the time. It’s particularly worse when I’m pregnant.

Yep!! All the time. Could be an iron deficiency, I would suggest going to the Dr =)

i know that i have bumped myself and vaguely register it because i was really busy cooking etc and then notice the bruise awhile later and struggle to remember what i did lol

Also take some photos of the bruises to show to your GP.

I would definitely get this checked by your GP as it is out of the ordinary. It will give you peace of mind to get the bruising checked.

may be you hit a bed side ? but actually get it checked with your gp..

sometimes i just forget that i walked into something or my daughter stepped on me and pulled the skin to hard, I don’t know if they really come from nowhere.

You may be deficient in a vitamin or mineral (iron, vit k etc) I would see your GP & have a blood test to make sure it’s nothing more than just bumping your leg

For me bruises tend to appear a few days after a bang, i find with kids it happens a lot and you tend to forget about it, but in saying that if it keeps happening i would ask you doctor about it as could be a sign of something like vitamin defficiancy etc

Yeah. It usually means I’ve walked into something, and by the time the bruise appears a couple of days later I can’t remember doing it.