These words all describe feeling or showing fear.
Afraid [not before noun] feeling fear; worried that something bad might happen:
There's nothing to be afraid of. Aren't you afraid (that) you'll fall?
Frightened: feeling fear; worried that something bad might happen:
a frightened child
She was frightened that the glass would break.
Scared (rather informal) feeling fear; worried that something bad might happen:
The thieves got scared and ran away.
afraid, frightened or scared?
Scared is more informal, more common in speech, and often describes small fears. Afraid cannot come before a noun. It can only take the preposition of, not about. If you are afraid/frightened/scared of somebody/something/doing something or afraid/frightened/scared to do something, you think you are in danger of being hurt or suffering in some way.
If you are frightened/scared about something/doing something, it is less a fear for your personal safety and more a worry that something unpleasant might happen.
I was terrified (that) she wouldn't come.
She looked at him with wide, terrified eyes.
Alarmed: afraid that something dangerous or unpleasant might happen:
She was alarmed at the prospect of travelling alone.
Paranoid (rather informal) afraid or suspicious of other people and believing that they are trying to harm you, in a way that is not reasonable:
You're just being paranoid
.afraid/frightened/scared of spiders.
…afraid/frightened/scared to open the door, etc.
Don't be afraid/frightened/scared/alarmed.
Adolescent fear: Adolescence is a complicated life phase when the body, feelings and mind of a person change. In this stage, all people are afraid of different things: somebody feels fear about his/her future; somebody feels fear about his/her present life. In these moments, hormone levels change all the time, and the person is confused about his feelings and thinking. Women are more perceptible than men of their body changes. Their bodies become strange to them. In this moment, a woman needs to control her body and thinks that if she becomes thin, she will control her body. So, many women begin to eat less and do a lot of exercise. But, they should understand that all things that they feel are normal, their body is changing, and they do not have to be scared or worried about how they or their bodies look, what other people think about the way they have to look or how they have to think. Adolescence is the most important life phase, because It is when some people define what kind of person he/she will be, and what kind of values are going to be important to him/her in future.