How would I go about telling my grandma Im pretty sure I have OCD?!

I know how you feel, there's pretty much 99.9% that I have it too. Even asked on here, and many all agreed that I have it pretty strongly. But anyways, I'm in the same situation, my boyfriend notices all the time, and comments on it, as does many of my friends.

Thing is, my parents think I exaggerate, when I don't. My boyfriend has even brought it up to my mother and she simply looked confusingly and laughed..

Just sit her down, and keep a calm head on your shoulders. OCD isn't uncommon, but many people don't understand it. She may think your being dramatic, but simply explain some things you do. OCD can be harsh in its own ways. Urges and temptation isn't something that can be taken lightly either. My life is pretty much being taken over by my OCD urges, temptations and habits. So I know where your coming from.

First off, she might not understand what it is and what its effects are. So do some research to show her possibly? Explain the rituals you do, and how you feel. That's an important one. Just to start the conversation, simply sit her down and say that yourself and others have noticed the ways you are doing things are similar to that of OCD characteristics. Make sure you don't argue, shout, complain etc.. at her reaction, she may not take lightly, but she may do. Either way, she'll hopefully accept you being honest to her, and hopefully you can do something about it to stop it getting any progressively worse.

Good luck!

OCD isn't uncommon. You can just say, "I think I have OCD". There's nothing wrong with having it.

Ask her to go with you to see a therapist so they can diagnose you.

Do you have to tell her? OCD is a something new. In her day they was no such thing as OCD, she may not understand.