26/11/2025
1. Intramuscular Injection (IM)
Where it is given: Deep into a muscle
Common Sites:
Deltoid (shoulder)
Thigh (vastus lateralis)
Buttock (gluteus)
Used for:
Vaccines (e.g., Tetanus)
Antibiotics
Vitamin B12
Why used:
Medicine absorbs faster than subcutaneous
Can give larger volume (2–5 ml)
2. Intravenous Injection (IV)
Where it is given: Directly into a vein
Common Sites:
Forearm veins
Hand veins
Used for:
Emergency medicines
IV fluids / drips
Painkillers
Why used:
Fastest absorption (direct to bloodstream)
Immediate effect
3. Subcutaneous Injection (SC / SubQ)
Where it is given: Just under the skin (fatty layer)
Common Sites:
Belly (abdomen)
Thigh
Upper arm (back side)
Used for:
Insulin
Heparin
Some vaccines
Why used:
Slow and steady absorption
Less painful
4. Intradermal Injection (ID)
Where it is given: Just inside the top layer of skin
Common Sites:
Forearm
Used for:
TB test (Mantoux test)
Allergy tests
Why used:
Very small amount needed (0.1 ml)
Medicine stays close to surface for testing
5. Intraperitoneal Injection (IP) (Medical/Research Use Mostly)
Where it is given: Into abdominal cavity
Used for:
Rare in humans; used in lab animals
Sometimes used for dialysis
6. Intraosseous Injection (IO)
Where it is given: Into bone marrow
Used for:
When veins are not accessible
Emergency situations
Why used:
Very fast absorption
Life-saving alternative to IV
7. Intra-articular Injection
Where it is given: Directly into joints
Common Sites:
Knee joint
Shoulder
Hip
Used for:
Steroids for joint pain
Hyaluronic acid for arthritis
8. Intrathecal Injection
Where it is given: Into spinal canal (CSF)
Used for:
Spinal anesthesia
Chemotherapy in the spine
Why used:
Medicine reaches spinal fluid directly
