Tingling in your left breast is most often caused by fluctuations in hormones that often occur during menstruation, perimenopause or pregnancy.
The changes in hormones and hormonal fluctuations can disrupt your delicate nerves that are in your breast area and cause tingling in the left breast or other breast.
Other causes of tingling in your left breast or even right breast are wearing tight clothing, taking certain medications, nerve irritation from injury or breast inflammation.
Another cause of tingling in the left or right breast is breast cancer.
However most breast tingling is nothing to worry about unless you experiences changes in your breast or lumps.
If your breasts continue to tingle and it doesn't get better or you feel a lump you should see a doctor and have a breast exam done to check for possible breast cancer.
Breast cancer does not just affect woman as it can also affect men as well.
The numb and tingling sensation in your breast might simply be the result of the compression of small nerve fibers in the chest wall or breast tissue.
This type of nerve compression can also cause a tingling sensation.
One possible culprit of the nerve compression and tingling breast is wearing a bra that doesn't fit properly.
I sometimes will get a tingling in my left and right breasts and sometimes at the same time but many times it's either the right or left breast.
Once it was a bra that was too tight and other times it was just hormonal fluctuations.
If the breast tingling does not go away within a week or less then it could be something more serious like breast cancer and if so you should get checked out to be safe.