---
title: Physiological Variables That Can Affect Blood
url: "https://arizonacollege.edu/blog/physiological-variables-that-can-affect-blood/"
type: post
date_published: 2013-09-12
date_modified: 2013-09-12
schema:
  @type: Article
language: en-US
word_count: 361
reading_time: 2 min
canonical: "https://arizonacollege.edu/blog/physiological-variables-that-can-affect-blood/"
categories:
  - "Health & Wellness"
topic:
  - Phlebotomy
---

# Physiological Variables That Can Affect Blood

Are you considering a career in
[the field of Phlebotomy](https://www.arizonacollege.edu/all-programs/medical-assisting/phlebotomist/)
? As you begin your training and become familiar with the numerous processes and
procedures of the job, you should also have an understanding of the various
physiological variables that can affect a patient’s blood when collecting
samples for testing.

One of the more obvious variables to consider is the age of the patient.
Compared with adults, newborns typically have higher values of red and white
blood cells. Elderly patients may have higher levels of creatinine present in
their blood samples, as kidney function tends to decline with age.

Diet can also affect the composition of blood. A diet that includes foods with
high sugar will produce high glucose levels in the blood that can last for
several hours. A diet that includes a lot of fatty foods will increase the fat
content in blood, making plasma appear cloudy. If the patient is not drinking
enough fluids and is dehydrated, this can also affect the blood, causing it to
become more concentrated.

Even geography can play a role, as altitude can greatly affect the number of red
blood cells in a patient’s blood. To meet oxygen needs, the body will produce
more red blood cells due to the decreased oxygen levels found at higher
altitudes.

Drug therapy treatments like chemotherapy can decrease white blood cells and
platelets, and alter the concentrations of blood analytes. Or, if the patient is
taking a drug with steroids or diuretics, this can increase calcium and glucose
levels and decrease the levels of sodium and potassium.

Because Phlebotomists are responsible for collecting blood samples before they
are taken to the laboratory for testing, it is important for them to be aware of
the various physiological factors that have the potential to affect and
influence test results. If you’re interested in playing a critical role in the
diagnosis and treatment of disease,
[contact Arizona College](https://www.arizonacollege.edu/request-information/)
to learn about our 
[Phlebotomy training program](https://www.arizonacollege.edu/all-programs/medical-assisting/)
.

---

_Information in this blog post is accurate as of September 12, 2013._

**Categories:** Health & Wellness