Is it normal to just randomly cry?

I would sy that you are depressed. Spontaineous crying is a sign of depression. It’s also a sign of raging hormones, but I would go with depression here. Have you made some compromises in your life that you are finding hard to live with? If so, fix them—to YOUR satisfaction. To thine own self be true. No matter how painfull this may seem, depression is much more painfull and can last a lifetime. If you allow yourself to remain in this state too long, the chemistry in your brain will change and today’s physicians will put you on drugs. You don’t want that. That is the road to hell, believe me. I was a nurse for 23 years and saw a lot of human potential wasted along the way by lazy doctors, understaffed teachers, social workers without proper resources—and patients too timid to stick up for themselves.

So fix what is wrong with your life now and continue to do what is right for you first in everything you do. This is not a selfish act. A selfish act would be to become debilitated due to depression and deprive the world of whatever unique resources you were born with and become a dependent, self-absorbed buzz killer with tendencies toward hypochondria. So, this is an act of self preservation. Enjoy your life, but be careful of the compromises we sometimes must negotiate with those closest to us.

I second what @Espiritus_Corvus has said. It’s not abnormal for people suffering depression to manifest with crying, extreme lethargy, physical ailments such as you describe and all sorts of things that lead to feelings of hopelessness, worthlessness, apathy… and worse. Sometimes it’s a transient thing; it goes away on its own. (It’s not uncommon at all for people to feel depression while already afflicted by grief at the loss of a loved one through death, divorce and other separation – and part of what you’re describing can be “normal grief” if you can pinpoint the cause and if it does go away on its own after time, or at least gets easier and easier to deal with, even if some sadness remains for a long time.)

When you can’t say “This is why I’m feeling bad” and work in some way to process the grief, exercise the hormones (by which I mean “exercise the body that they’re in”) and “deal with it”, then it’s time to seek professional help. I would also caution against long-term medication, but not all medication is bad if it helps you “for a few weeks or months” perhaps, to get over the worst symptoms until your body and mind can take over your emotional (and brain chemistry) equilibrium.

Do you have any counselors, a minister or someone else not “a crush” or “an ex” or “a potential mate” (because you don’t want to compound your problems!) that you can talk to for starters? It’s best for this if you can find someone who doesn’t already have an emotional attachment to you, is bound by a code of ethics not to take advantage of you in a vulnerable position, and has some experience dealing with depressed young people. (And someone with whom you’re less likely to attempt a romantic interest. Seriously, because that happens, and it makes things worse, not better.)

I remember as a teenager just bawling for no reason. I just figured I needed a good cry every once in a while. I eventually outgrew it.

Uh-oh. You might have Pseudobulbar Affect… totally kidding, what a bullshit disease concocted by pharmaceutical companies
Or you could just be a normal teenager with whacked out hormones and too many emotions you aren’t skilled in coping with yet. You’ll be fine. Crying releases anxiety and endorphins. Get it out, then shut it down in public. Definitely stop crying to your crush. Boys hate that.

Even small things can do this to people like diet changes, quitting smoking/coffee. If you have been holding a lot of emotion in then this is perfectly normal. If it continues then it is likely depression. Most people experience it to some degree including myself.

It’s usually a sign of depression if it is happening regularly. It can be hormonal or have a hormonal component. If there is something specifically very sad going on in your life it can just be deep sadness, not necessarily depression, I think of them as two different things, but they go together a lot.

Are you a teenager? It’s pretty common for teens to go through things like this. Are you feeling lonely or like you aren’t fitting in with your friends? Loneliness can be a big cause of depression. If you don’t feel better soon consider doing something to occupy your time and meet new people. Either a sport, hobby, or a job. Do you have a job or something that you do fairly regularly to help busy your time? If none of that works consider seeing a therapist maybe who can help you think through why you are crying.

One thing you can do on your own is when you start to cry ask yourself, why am I crying? Force yourself to get to the root cause.

Keep in mind that Fluther is not a therapist, and don’t read too much in “diagnoses” here. If you fear you are depressed, get counceling. It could also be ordinary teenager stuff that so many people go through.