Blood collection has many benefits. However, various complications may also arise from blood collection. The frequency of these complications is very low and can be nullified if proper training is provided to the nurses.


In medical terminology, syncope means the sudden loss of consciousness due to the loss of supply of blood to the brain.

It is commonly referred to as “fainting” or “passing out”. Before fainting, the person may experience symptoms like becoming light-headed, dizzy, body turning cold or the vision becoming blurry. This happens due to low blood pressure.

There are 3 types of syncope.

  • Vasovagal syncope
  • Carotid sinus syncope
  • Situational syncope

Syncope usually occurs in the elderly. Howbeit, healthy and young individuals may also contract it.

If a person gets vasovagal syncope by seeing their blood, then immediately lie them down flat and lift their legs.

The figure shows the position of the man to help him regain his consciousness image
Figure: shows the position of the man to help him regain his consciousness.


It is the swelling around the site from where blood is drawn, which results in the leaking of the blood in the surrounding tissues.

There are some reasons as to why hematoma may be contracted. 

  1. The needle may have passed through the vein.
  2. Not enough pressure may be applied after venipuncture.
  3. Applying pressure to the bandaged area.
  4. Chances of hematoma are increased in patients who are on anticoagulant therapy as their blood is thinned and decreases its ability to clot.
  5. Blindly searching the vein.

While drawing blood, avoid the basilic vein which is near the brachial artery and several other nerves. The reason for this is that it is very sensitive and bruises the most. Nevertheless, if you mistakenly do penetrate the basilic vein, it will cause severe pain and bleeding. 

Also, avoid the forearm, the most preferable region from which blood is collected is the anti cubital fossa. The anti cubital fossa is commonly known as the bend of the elbow.

Usually, the complication that arises from drawing blood for samples is the minor case of hematoma. The chance of its occurrence is 12.3%. However, the more serious case of hematoma has a lesser chance of occurrence which is 3.4%.

Figure shows the area of arm affected with hematoma
Figure: shows the area of arm affected with hematoma.


Sometimes, individuals undergoing blood collection or testing may develop the condition of hypersensitivity type 1. This complication arises due to the hypersecretion of histamine and histamine-like substances.

The reaction that the patient may develop is of 2 types.

  1. Systemic reaction
  2. Localized reaction
showing the hypersensitivity type 1 reaction image
Figure: showing the hypersensitivity type 1 reaction.
image source:


Although, there are many signs and symptoms of the patients that are suffering from complications during blood collection and testing. I have mentioned a few of them below.

  • Diarrhea
  • Urticaria
  • Nervousness
  • Nausea and vomiting
  • Convulsions
  • Abdominal or back pain
  • Respiratory depressions
  • Itching of skin
  • Low blood pressure
  • Feeling confused


Phlebitis is the inflammation caused to the vein by the insertion of a cannula.

The main complication of phlebitis is that it produces clots in the blood vessels which results in thrombosis. Phlebitis has mainly 3 causes which are: chemical, mechanical and infectious.

Make sure that before the insertion of the cannula, the surface of the skin is cleaned as the micro-organisms present may be the reason for the contraction of phlebitis.

As phlebitis is a sort of infection, therefore it will entirely show symptoms of infections which are: redness, pain, warmth, tenderness, and enlargement of the veins that are affected.Nonetheless, phlebitis and sepsis are amongst the rare complications of blood collection.

Skin Puncture

Skin puncture is used to obtain an adequate sample of blood in cases where venipuncture or any other methods are difficult.

Samples that are obtained from infants, who are under the age of 6 months, are usually collected with the help of the renowned method of heelstick. In this method, blood is collected from the heel of the infant.

 In contrast, the specimen of those who are above the age of 6 months is collected by finger sticks. The common sites for blood collection in this method are fingers. As well as that, if the age of the individual is above 6 months, blood can also be drawn from the ear lobes by the method of skin puncture. Earlobes are a good alternative because it helps in the assessment of the pH, pO2, and pCO2 of the arterial blood.

Various samples are collected in microtainers in different colored caps so that the identification of microtainer additives is made easier.

If there occurs a case of arterial puncture, then instantly withdraw the tourniquet and put pressure on the area for at least 5 minutes or until the bleeding stops. After the bleeding stops, make sure you apply fresh tape, bandage, or gauze. Subsequently check the pulse and blood pressure but not before making sure that everything is intact.

Figure shows the procedure of skin puncture.
Figure: shows the procedure of skin puncture.

Standards of blood collection:

  1. Gather the equipment
  2. Make acquaintance with the patients
  3. Select the site
  4. Put the gloves on
  5. Disinfect the surface of the skin from which blood is to be drawn
  6. Draw blood
  7. Fill the tubes with the sample of blood
  8. Put the samples in the correct order

Frequently Asked Questions

Q1. What is venipuncture?

Venipuncture is the intravenous suction of blood using a syringe. This procedure holds significant importance as it helps in the prognosis of many diseases.

Q2. What is the difference between venipuncture and phlebotomy?

Venipuncture is the process by which you can collect blood directly from the vein. Whereas, in phlebotomy, you open the vein to withdraw or let out blood_ venesection.

Q3. What are the 3 methods of blood collection?

Following are the 3 popular methods for the collection of blood.
1. Venipuncture sampling
2. Arterial sampling
3. Fingerstick sampling

Q4. What is the most common complication of blood collection?

Hematoma and minor bruising are the most common complications of blood collection.

Q5. How to prevent nerve damage?

The best way to prevent nerve damage is to make sure that along with choosing the most prominent vein, you penetrate the needle properly into the vein. Use a smaller needle relative to the vein’s depth.

Q6. What causes hemolysis during blood collection?

Phlebotomy may result in hemolysis which is caused due to improper tube mixing, incorrect size of needle, excessive suction, incorrect filling of tubes and prolonged tourniquet.

Q7. What is the treatment of hemolysis?

Treatments of hemolysis includes plasmapheresis, blood and marrow stem cell transplants, blood transfusions, medicines, surgery, and change of lifestyle.



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