Merck Manual

Please confirm that you are not located inside the Russian Federation

Yes No

Leave this Site?

The link you have selected will take you to a third-party website. We do not control or have responsibility for the content of any third-party site.

Continue Cancel
Merck Manual
Consumer Version
The trusted provider of medical information since 1899
Health Topics & Chapters
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Merck Manual
Consumer Version
The trusted provider of medical information since 1899
Health Topics & Chapters
A
B
C
D
E
F
G
H
I
J
K
L
M
N
O
P
Q
R
S
T
U
V
W
X
Y
Z
Home /
Quick Facts: Blood Disorders /
Anemia /
... /
Overview of Anemia /
IN THIS TOPIC

What is anemia?

What causes anemia?

What are the symptoms of anemia?

How do doctors tell if I have anemia?

How do doctors treat anemia?

OTHER TOPICS IN THIS CHAPTER

Anemia
Overview of Anemia
Iron Deficiency Anemia
Sickle Cell Disease

Test your knowledge

HIp Fractures
The hip joint consists of several areas: the pelvis, then the round upper end (head) of the thighbone (femur), then the area below the head of the femur (also called the neck of the femur), and then two large bumps beneath the neck of the femur (also called trochanters). Most hip fractures occur in which of the following areas of the hip? 

More Content

Loading
Quick Facts

Overview of Anemia

By

The Manual's Editorial Staff

Last full review/revision Apr 2019
Click here for the Professional Version
Get the full details
NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version

What is anemia?

Anemia is not having enough red blood cells or hemoglobin. Red blood cells carry oxygen from your lungs to all your organs. Hemoglobin is the substance inside your red blood cells that actually carries the oxygen.

  • When you have too few red blood cells or too little hemoglobin, your blood can’t carry all the oxygen your body needs

  • Anemia causes tiredness and weakness

  • There are many causes of anemia

  • It's important to test for anemia as you get older since it can shorten your life span

What causes anemia?

Causes of anemia include:

  • Losing a lot of blood because of an injury, heavy menstrual periods, or GI or urinary tract problems (chronic bleeding)

  • Not making enough red blood cells because your body lacks enough iron, vitamin B12, or folate, or because you have leukemia or another cancer

  • Your body destroying too many red blood cells

What are the symptoms of anemia?

Symptoms depend on how severe your anemia is.

Mild anemia causes:

  • Feeling weak and tired

  • Paleness

Severe anemia causes:

  • Feeling faint and dizzy

  • Feeling thirsty

  • Sweating

  • Weak, fast pulse

  • Lower leg cramps during exercise

  • Shortness of breath

  • Chest pain

How do doctors tell if I have anemia?

Doctors do a blood test to measure your levels of hemoglobin and red blood cells. They may do other tests to find the cause of your anemia.

How do doctors treat anemia?

If a health problem is causing your anemia, doctors treat that health problem. Treatment depends on the type of anemia you have. Doctors may treat anemia with:

  • Iron supplements, taken as pills or by IV

  • Other supplements, such as vitamin B12 or folate

  • Transfusion of red blood cells, for severe anemia

  • Medicine that causes your body to make more red blood cells

NOTE: This is the Consumer Version. DOCTORS: Click here for the Professional Version
Click here for the Professional Version
© 2020 Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA)
Bruising and Bleeding
Iron Deficiency Anemia
Others also read
Overview of Anemia Overview of Anemia
Anemia of Chronic Disease Anemia of Chronic Disease
Aplastic Anemia Aplastic Anemia

Also of Interest

Videos

View All
Blood Clots: Plugging the Breaks
Video
Blood Clots: Plugging the Breaks
Bleeding occurs when there is a break in a blood vessel wall. Control of bleeding (hemostasis)...

SOCIAL MEDIA

Merck and the Merck Manuals

Merck & Co., Inc., Kenilworth, NJ, USA is a global healthcare leader working to help the world be well. From developing new therapies that treat and prevent disease to helping people in need, we are committed to improving health and well-being around the world. The Merck Manual was first published in 1899 as a service to the community. The legacy of this great resource continues as the Merck Manual in the US and Canada and the MSD Manual outside of North America. Learn more about our commitment to Global Medical Knowledge.

TRUSTe
TRUSTe

This website is certified by Health On the Net Foundation. Click to verify. This site complies with the HONcode standard for trustworthy health information:
verify here.

© 2020 Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc., Kenilworth, NJ, USA
TOP