Does blood go bad?

In this brief guide, we will discuss the following question, “does blood go bad?”, the reasons why blood goes bad, the main functions of the blood, how it is stored, and other queries related to this topic.

Does blood go bad? 

Yes, blood goes bad. The blood expiration date is 42 days or 6 weeks when refrigerated at 6 degrees Celsius. That means that the blood donated should be used within this period and does not last for very long.

However, some people may experience disadvantageous effects such as blood infections, and respiratory infections along with other problems if they receive blood stored for more than two to three weeks or 14 to 21 days.

Blood transfusion or donation is required for people who lost a great deal of blood due to an accident, during a specific surgery, or have a medical condition that requires regular blood transfusion such as severe anemia, leukemia, or sickle cell anemia.

Why does donated blood go bad?

The reason is that after two to three weeks the red blood cells present in the blood, which have an important role in delivering oxygen to the different cells of the body, begin to lose their delivery capacity. 

Moreover, after blood donation and during the storage of the blood, the level of nitric oxide (NO), a vasodilator molecule that widens the blood vessels due to its relaxing effect and as a result lowers the blood pressure, drops down. However, giving blood with low nitric oxide levels may not provide good oxygen delivery to the body cells.

How does blood work?

Delivering needed oxygen and nutrients like glucose, amino acids, and fatty acids to the living cells of the body is the main function of the blood, however, it is also needed in getting rid of carbon dioxide.

Here are the four components of the blood, the plasma, the red blood cells, the white blood cells, and the platelets. Each compound in blood has its unique function.

About half of our blood consists of plasma. Plasma consists of 55% of your blood. However, 92% of the plasma is water and the remaining 8% are nutrients, vitamins, and hormones.

The red blood cells, the white blood cells, and the platelets consist of 45% of the remaining blood fluid. The red blood cells’ main function is to carry the oxygen through the body, from the lungs to the cells or vice versa. However, the white blood cells are involved in the immune system and the body’s defense system against diseases and infections.

Regarding the platelets, their function is to prevent bleeding through blood clotting.

Furthermore, there are different types of blood donations. The type depends on the case. For example, people suffering from anemia receive red blood cell transfusion.

What happens to unused donated blood?

Like any other medical waste, unused blood is incarnated. However, as mentioned earlier blood fluid has several components, and the donation of each one is related to the patient’s case. Hence, expired components are utilized in the research.

Moreover, to avoid such waste several ways were developed to preserve blood and its components for a longer time. Platelets, a part of the blood fluid, can be stored for only five days at a controlled temperature. To ensure efficient storage, a platelet agitator is used. However, plasma can be frozen which increases its shelf life for an extra year.

However, freezing the blood is a way to preserve it for 10 years, but this way of preservation is not advised by the experts.

Furthermore, there are few studies and researches about producing synthetic blood, hence it is still under testing. Moreover, artificial blood cannot replace the function of real blood.

Does your blood type affect your donation?

Before donation, determining your blood type and your rhesus factor is a must, so a test should be conducted for this reason. We have 4 blood groups: A, B, AB, and O, and two rhesus factors. These 4 groups with the two rhesus factors give 8 blood categories.

The Rh factor refers to the presence or the absence of a specific protein which is an antigen involved in the immune system. You will be Rh-positive if the antigen is present and if it is absent you will be Rh-negative.

However, the donor blood type and rhesus factor should be compatible with those of the other patient or the person you are donating to.

Furthermore, one blood type which is the O negative is considered a universal blood donor.


In this brief guide, we discussed the following question, “does blood go bad?”, the reasons why blood goes bad, the main functions of the blood, how it is stored, and other queries related to this topic.


Was this helpful?

Thanks for your feedback!