1. Cut
A cut is a tear or opening in the skin which is caused by an external factor or from the skin wearing away. This could be from a fall, banging into something or being cut by something sharp. Signs and symptoms: Opening of the skin, blood, redness. If the cut is infected there may also be signs of: discharge or pus coming from the cut, fever, increased pain, swelling, or warmth in the affected area. Treatment: Clean the cut, cover with a dressing or plaster. If the wound is infected injury you must see a doctor. To stop the infection from spreading, treatment most often consists of an antibiotic cream or ointment or a prescription for oral antibiotics.

2. Bruise Signs and symptoms:
A fresh bruise is often reddish. It will then turn blue or dark purple within a few hours, then yellow or green after a few days as it heals.
A bruise is commonly tender, and sometimes even painful for the first few days, but the pain usually goes away as the colour fades.
Treatment:
Most bruises will disappear within a few days or a week of injury without the need for any treatment but you can limit the internal bleeding by cooling the area with a cold compress or an ice pack wrapped in a towel.
Internal bruising cannot be seen on the surface of the skin but the person can suffer from pain and swelling. If this occurs you must seek further medical advice from the hospital.
Black and blue marks are often associated with bruises. A bruise appears on the skin due to trauma. Examples of trauma are a cut or a blow to the area.
Blood from damaged blood vessels beneath the skin collects near the surface of the skin resulting in the appearance of bruising. The most common causes of bruising are:
Bumps or any abnormal force applied to the body
Falls
Joint sprains
Muscle strains
Sporting injuries

3. Strain Signs and symptoms: Treatment:
Swelling, bruising, or redness due to the injury.
Pain at rest.
Pain when the specific muscle or the joint in relation to that muscle is used.
Weakness of the muscle or tendons.
Inability to use the muscle at all
Treatment:
Strains can usually be treated with rest, ice, compression and elevation. You should try to start moving and doing light stretches with the affected areas as soon as it is not too painful to do so. Ordinary painkillers such as paracetomal can be used to help ease any pain and also anti inflammatory tablets to reduce any swelling or inflammation.
A strain is an injury to a muscle or tendon in which the muscle or tendon fibres tear as a result of overstretching.

4. Sprain
A sprain occurs when one or more of your ligaments have been stretched, twisted or torn, usually as a result of excessive force being applied to a joint. Sprains are most likely to occur if you over-reach, change direction or speed suddenly, fall and land awkwardly or collide with an object or person.
Signs and symptoms:
pain around the affected joint
being unable to use the joint normally or being unable to put weight on it
swelling
bruising
tenderness
Treatment:
Minor sprains can usually be treated with rest, ice, compression and elevation. You should try to start moving a sprained joint as soon as it is not too painful to do so. Ordinary painkillers such as paracetomal can be used to help ease any pain.

5. Concussion
Treatment:
apply a cold compress to the injury to reduce swelling 
take paracetomal to control pain –
get plenty of rest and avoid stressful situations where possible
only return to work, college or school when you feel you have completely recovered
only drive a car or ride a bike when you feel you have completely recovered
do not play any contact sports for at least three weeks without seeing your GP first
make sure you have someone to stay with you for the first 48 hours after the injury – this is in case you experience more serious follow-up symptoms
For more serious concussion:
If you or someone in your care has any of the signs or symptoms listed below, go to your nearest accident and emergency (A&E) department as soon as possible:
unconsciousness or lack of consciousness, such as problems keeping your eyes open
mental confusion, such as forgetting who or where you are
any drowsiness that goes on for longer than one hour when you would normally be wide awake
any problems understanding or speaking
any loss of balance or problems walking
any weakness in one or both arms or legs
any problems with eyesight
a very painful headache that will not go away
any vomiting
any fits or seizures
clear fluid coming out of the ear or nose
bleeding from one or both ears
sudden deafness in one or both ears
Concussion is the sudden but short-lived loss of mental function that occurs after a blow or other injury to the head.
Signs and symptoms:
confusion 
headache
dizziness
nausea
loss of balance
feeling stunned or dazed
disturbances with vision
difficulties with memory

6. Cramp Signs and symptoms:
the affected muscles will become tight and painful and the feet and toes will be stiff.
After the cramps have passed, you may have pain and tenderness in your legs for several hours.
Treatment:
Drink lots of fluids
Massage the affected area
Stretch and massage the muscle.
Take a warm shower or bath to relax the muscle
Try using an ice or cold pack if necessary
Cramp can be caused by:
overusing a muscle
Dehydration
muscle strain
simply holding a position for a long period of time

7. Blister Signs and symptoms:
Small pockets of fluid that usually form in the upper layers of the skin
May be filled with a clear fluid or blood
Can be red, painful and itchy
Treatment:
Blisters often do not need any treatment. Do not try to pierce the blister. You can cover it with a plaster if necessary. If the blister bursts keep it clean and dry
If you think your blister has become infected, you will probably need to get antibiotics from your doctor. If you have severe blisters you should also contact a medical professional
If your blister is painful you can apply a ice pack (covered in a towel so that it does not stick to the blister) to relieve some of the pain.
Blisters can be caused by:
Friction e.g. poor fitting footwear rubbing on an area
Skin reaction e.g. when exposed to excessive heat i.e. sunburn, burns and scalds
Medical conditions e.g. chicken pox, cold sores