Fatigue and pallor (paler-than-usual skin) are the most well-known signs of iron deficiency. However, it can also cause a range of unexpected symptoms that are often overlooked.

Iron deficiency is one of the most common nutrient deficiencies worldwide. Here are five lesser-known symptoms that could indicate low iron levels.

Iron is important for muscle health, including the tongue. Low iron levels can lead to a swollen, inflamed, or unusually smooth tongue (glossitis).

Some people also experience soreness, changes in taste, or difficulty swallowing.

Since iron helps transport oxygen, low levels can affect the cells that maintain healthy muscles and tissues. If your tongue feels swollen or uncomfortable, a blood test can help determine if iron deficiency is the cause.

Pica is a craving for nonfood items, such as ice, clay, dirt, or paper. This unusual symptom is strongly linked to iron deficiency, though researchers aren’t entirely sure why.

One of the most common forms of pica in iron-deficient people is pagophagia, or compulsively chewing ice. Some studies suggest that eating ice may increase alertness and temporarily improve brain function in people with low iron levels.

If you crave nonfood items, especially ice, it may be worth getting your iron levels checked.

RLS causes an uncomfortable urge to move your legs, often worsening at night and interfering with sleep. While its exact cause isn’t fully understood, research suggests a strong connection between RLS and low iron levels in the brain.

Iron is involved in dopamine production, a neurotransmitter that helps regulate movement. A lack of iron may disrupt dopamine activity, triggering RLS symptoms.

Studies show that iron supplementation can improve RLS symptoms in people with iron deficiency.

Iron deficiency can disrupt the hair growth cycle, leading to thinning hair or increased shedding.

When iron levels are low, the body prioritizes sending oxygen to vital organs rather than to hair follicles. This can cause hair to enter the shedding phase (telogen effluvium) sooner than usual.

While mild hair shedding is natural, excessive hair loss or noticeable thinning could be a sign of low iron. If iron deficiency is the cause, restoring expected iron levels may help hair regrow over time.

A persistent whooshing, ringing, or pulsing sound in the ears — known as pulsatile tinnitus — can be a lesser-known symptom of iron deficiency anemia.

Pulsatile tinnitus is caused by a change in blood flow in the vessels near the ears. When iron levels are low, blood may be thinner and move more quickly through the body, creating turbulence that can be heard as a whooshing sound in the ears.

Since iron helps transport oxygen, a deficiency can also lead to reduced oxygen levels in the blood, affecting overall circulation and potentially contributing to tinnitus.

You might also experience:

If you think you have iron deficiency, consider making an appointment with a healthcare professional to discuss your concerns. With the right treatment, your symptoms can improve.

Treatment for iron deficiency depends on the cause and severity. You might benefit from one or more of the following treatments:

  • Dietary changes: Eating more iron-rich foods, such as red meat, poultry, fish, beans, lentils, tofu, spinach, and fortified cereals, can help.
  • Iron supplements: Iron pills are often recommended if diet alone isn’t enough. These should be taken as prescribed, as too much iron can cause side effects.
  • Vitamin C intake: Pairing iron-rich foods with vitamin C sources (like citrus fruits, bell peppers, and tomatoes) can help improve absorption.
  • Treating underlying causes: If iron deficiency is due to heavy menstruation, digestive symptoms, or chronic conditions, treating the root cause may help prevent it from recurring.
  • Iron infusions: In severe cases, you may need to get an iron IV infusion.

Iron levels can take a few months to return to expected levels, so consistency is key. A healthcare professional can help determine the best approach based on your individual needs.

Iron deficiency doesn’t always cause obvious symptoms. Signs like tongue swelling, pica, restless leg syndrome, hair loss, and unusual ear noises may indicate low iron levels, even if you don’t feel noticeably fatigued.

If you suspect an iron deficiency, a healthcare professional can perform a blood test to check your iron levels. Treatments — like iron-rich foods, supplements, or addressing underlying causes of low iron absorption — can significantly improve your symptoms.