Risks & Complications of Venesection

Venesection is generally safe, provided it is performed in line with our VBP guidelines. However, occasionally one or more of the following complications may arise.

  • Haematoma: the risk of this can be reduced if the health care professional applies firm pressure to site after venesection needle removal for 2-5 minutes, and then applies a firm dressing. Depending on the size of the haematoma, it can take several weeks to resolve.

  • Nerve irritation: this can occur as a result of extrinisic nerve compression from a haematoma or, from the result of the venepuncture procedure itself. Therefore, it remains the practitioner's responsibility to use caution during the venesection procedure. If a patient complains of weakness, burning or any degree of paraesthesia during, immediately after, or within the first week following routine venepuncture then doctors require to be informed to either refer on, or organise diagnostic tests. Studies by Newman and Waxman (1996) found that 70, 90, and 96% of venepuncture-related nerve injuries resolved within 1, 2 and 6 months, respectively.


  • Nerve injury: can be as a direct result of venepuncture. The patient will complain of immediate sharp, acute pain, that can shoot up and down arm and hand, parathesia (tingling and pins and needles). The pain will remain even after needle removal. Inform doctor immediately for further tests and investigations.


  • Compartment syndrome: is when there is increased pressure within a muscle compartment of the arm or leg. It is most often due to injury, so in venesection, if a vein or artery is accidently damaged it can cause bleeding within the muscle of the forearm which then causes increased pressure. This pressure increase causes nerve damage due to decreased blood supply. Symptoms include severe pain, numbness and decreased range of movement. Treat by elevating arm, icepacks and inform Doctors in case surgery is required (fasciotomy).


  • Arterial puncture: if an artery is accidentally punctured there will be a bright red, spurt of blood. Remove needle and apply firm pressure for 5 minutes to reduce risk of haematoma. If a haematoma develops and causes symptoms notify doctors immediately.


  • Delayed bleeding: sometimes bleeding can recommence once patient has left the department. Advise patients that this may occur (rare) and be vigilant for any:
    • swelling that is large or increasing in size
    • numbness or pins and needles in the arm, hand or fingers
    • severe or worsening pain
    • coldness or paleness of the lower arm, or hand of the affected arm

Advise the patient to:

Raise their arm and apply firm pressure.

Go immediately to the Accident and Emergency department at their nearest hospital or dial 999, remembering to continue to raise their arm and apply firm pressure over the site of needle entry on your way to hospital.


  • Tendon injury: If a needle is inserted into a tendon it will cause pain and decreased function. Further tests may be required, such as MRI.


  • Vasovagal fainting: fainting can occur at any time and patients undergoing venesection procedure should never be left alone. If patients are prone to faint always advise then to inform the staff before any procedure, so appropriate steps may be taken (lie them flat etc). If patients are lying flat remember to sit them up slowly and must not leave unless they have eaten and drank plenty of fluids. Observations pre and post venesection are also important. 

Discharge Advice for Patients

  • There is a risk of fainting so that on their first occasion of venesection or subsequently (according to their individual response) they should avoid driving and not operate machinery that day.
  • Maintain the dressing for 2 to 3 hours after the procedure. If the site bleeds after leaving the department the patient should elevate arm, apply firm, local pressure return to the department if they have just left, or follow the above delayed bleeding advice if at home. If the department closes at the end of the day all patients should be informed of an alternate contact number such as 999.
  • If feeling faint the patient should sit down, ask for help (if any is available) and bend their head towards the knees.
  • Drink at least one litre of extra fluid (water or other suitable choice) and to avoid alcohol.
  • Avoid heavy lifting or other strenuous exercise.
  • Observe for bruising at the venepuncture site and notify staff of any tingling or swelling in the arm or hand.
  • Avoid alcohol on day of venesection

Other issues

Other issues around venesection can include, intolerance of the procedure, difficult gaining venous access, anaemia and fatigue. Nurses should be mindful of this and reassure patients

Finally, it is important to maintain regular consultations with GH patients to support them physically and mentally to live well with GH.


Learning points

  • Nurses who undertake regular phlebotomy and venesections should not only aware of the risks but be familiar with how to treat any complication that arises.
  • It is imperative that all patients undergoing venesection are given advice on what to do, and who to contact if a complication arises post discharge.
  • Advice should be given to patients to eat well and drink plenty of fluids the day before and the day of venesection.
  • Fluids and food should be offered to patients undergoing venesection.
  • Post venesection a reminder should be given not to undertake heavy lifting or strenuous exercise to minimise the risk of a secondary bleed or haematoma formation.
  • Advise against drinking alcohol on the day of venesection

Next steps

Conclusion and post-test