Iron deficiency occurs when your body doesn’t have enough of the mineral iron.

Your body needs iron to make hemoglobin, a protein in red blood cells that enables them to carry oxygen around the body.

If your body doesn’t have enough hemoglobin, your tissues and muscles won’t get enough oxygen to be able to work effectively. This leads to a condition called anemia.

Although there are different types of anemia, iron deficiency anemia is the most common worldwide (1).

Common causes of iron deficiency include:

• inadequate iron intake due to a diet that doesn’t provide the daily nutritional needs or that’s heavily restricted
• inflammatory bowel disease
• increased iron requirements during pregnancy
• blood loss through heavy periods or internal bleeding

Iron deficiency can result in symptoms that can affect your quality of life. These include shortness of breath, tiredness, and reduced concentration (2Trusted Source).

Signs and symptoms of iron deficiency vary depending on:

• the severity of the anemia
• how quickly it develops
• your age
• your current state of health

In some cases, people experience no symptoms.

1. Unusual tiredness

Feeling very tired is one of the most common symptoms of iron deficiency. This symptom is common in people who don’t have enough iron (3Trusted Source, 4Trusted Source).

This fatigue happens because your body lacks the iron it needs to make a protein called hemoglobin, which helps carry oxygen around the body.

Without enough hemoglobin, less oxygen reaches your tissues and muscles, depriving them of energy. Your heart also has to work harder to move more oxygen-rich blood around your body, which can make you tired (1).

Since tiredness is often considered a normal part of a busy, modern life, it’s difficult to diagnose iron deficiency with this symptom alone.

However, many people with iron deficiency experience low energy alongside weakness, feeling cranky, or having difficulty concentrating.

2. Paleness

Pale skin or pale coloring of the inside of the lower eyelids are other common signs of iron deficiency (5Trusted Source, 6Trusted Source).

The hemoglobin in red blood cells gives blood its red color, so low levels during iron deficiency make the blood less red. That’s why skin can lose its healthy color or warmth in people with iron deficiency.

This paleness in people with iron deficiency can appear all over the body, or it can be limited to one area (7). This includes the:

• face
• gums
• inside the lips or lower eyelids
• nails

This is often one of the first things doctors will look for as a sign of iron deficiency. However, it should be confirmed with a blood test (6Trusted Source).

Paleness is more commonly seen in moderate or severe cases of anemia (7).

If you pull your lower eyelid down, the inside layer should be a vibrant red color. If it is a very pale pink or yellow color, this may indicate that you have iron deficiency. In people with darker skin tones, this may be the only area it is noticeable.

SUMMARY

Paleness in areas such as the face, lower inner eyelids, or nails may be a sign of moderate or severe iron deficiency. This is caused by lower levels of hemoglobin, which gives blood its red color.

3. Shortness of breath

Hemoglobin enables your red blood cells to carry oxygen around your body.

When hemoglobin levels are low during iron deficiency, oxygen levels will also be low. This means your muscles won’t receive enough oxygen to do normal activities, such as walking (8Trusted Source).

As a result, your breathing rate will increase as your body tries to get more oxygen. This is why shortness of breath is a common symptom (4Trusted Source).

If you find yourself out of breath doing normal, daily tasks that you used to find easy, such as walking, climbing stairs, or working out, iron deficiency could be to blame.

SUMMARY

Shortness of breath is a symptom of iron deficiency, since low hemoglobin levels mean the body isn’t able to transport oxygen to muscles and tissues effectively.

4. Headaches and dizziness

Iron deficiency may cause headaches, particularly in women (9Trusted Source).

This symptom seems to be less common than others and often occurs with lightheadedness or dizziness (4Trusted Source).

The link between iron deficiency and headaches is still unclear.

Headaches may occur because low levels of hemoglobin in red blood cells mean that not enough oxygen reaches the brain. As a result, blood vessels in the brain may swell, causing pressure and headaches (10).

Although there are many causes of headaches, frequent, recurrent headaches and dizziness could be a sign of iron deficiency.

SUMMARY

Headaches and dizziness could be a sign of iron deficiency. The lack of hemoglobin may mean that not enough oxygen reaches the brain, possibly causing its blood vessels to swell and create pressure.

However, these symptoms tend to be a lot less common. You would need to have iron deficiency for a long time to experience them.

SUMMARY

In cases of iron deficiency, the heart has to work extra hard to transport oxygen around the body. This can lead to irregular or fast heartbeats and even heart murmurs, an enlarged heart, or heart failure.