Why am I so nervous for no reason?

Hm, I would not be able to tell you why you are nervous without knowing more details about the scenarios that you get nervous in. I do know that some people get triggered and that makes them nervous even though they're okay. Some people have general anxiety disorder. I don't know if this is the case for you because as I have stated I don't know you nor am I able to diagnose you.

Perhaps you are stressed about something in your life that's not too apparent? Such as finals? A difficult family situation? Also, you're right caffeine and other stimulants cause anxiety or make it worse. This includes stimulant based meds like Adderall and Wellbutrin, so if you've recently started taking stimulants or increased your intake, that's a likely cause. (nicotine as well, contrary to popular opinion) Also lack of sleep usually cases an increase in anxiety, so get more sleep if possible.

It's normal to become nervous for no reason at all. it's just a natural reaction we have but, you can always find different ways to try to distract yourself or calm down.

Being nervous happens to everyone at some point in their lives. It could be for a number of reasons or even make no sense at all. It could be that something in your life has recently changed or your experiencing new things or you've been working longer than usual, maybe have more pressure on getting work done. If you feel this way all of the time then it may be an idea to try and talk to someone about it, a friend, family member, a GP or possibly a therapist if needed.

It may just have something to do with your nerves and sometimes you are nervous and you just don't know it.

There is always a reason for feeling nervous and it is important to work out and identify what this is :)

Unexplained nervousness could be a sign that you are experiencing anxiety. You could have an upcoming outing, test, or meeting that you are anxious about.

There are many reasons as to why you could be nervous, and only you can really know why, it's hard to figure out sometimes, it takes time, but if you can find a distraction that may help, something creative to help turn the anxieties into something positive, like art or music, everyone has their own thing, you just might of not found it yet, it takes time. Failing that make sure you have a good diet and are getting enough sleep, sleep deprivation and/or malnutrition/dehydration can make you nervous, if you're concerned, I suggest seeking medical help :D Don't let the anxieties affect your day to day life, if they are, that's when you should be seeking medical help :D

You might have anxiety! Sometimes nervousness is not your fault. You might be anxious because of a trigger or for no reason at all.

Nervous means a trigger to action, so our mind is telling you something. Our intuition helps us determine this things. You are the expert on your life. Write down what you think it could be. Seek professional advise, be brave! Commit to your well being!