Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache? Could anemia cause severe headache?