Sometimes headaches and tense muscles signal a more serious issue.
By Krystnell Storr
Iron Deficiency Anemia
Watch out for: Constant fatigue
Lack of iron in your diet (or the body's inability to absorb the mineral) can significantly drain your energy. Iron helps make red blood cells, which carry oxygen from the lungs to the rest of the body; low levels mean your heart has to work harder to move around oxygen-rich blood. Undiagnosed iron deficiency can eventually lead to arrhythmia, a heart murmur, an enlarged heart or even heart failure.
Watch out for: Pounding headaches
Hypertension is usually a symptomless disease, but if you start experiencing headaches, shortness of breath, nosebleeds or severe anxiety, you might be in hypertensive crisis. These stresslike symptoms may indicate that your blood pressure is 180/110 mm Hg or above, which is considered a danger zone. Ignoring the symptoms could leave you vulnerable to stroke, loss of kidney function and heart attack.
Watch out for: Unexplained changes in weight
Autoimmune conditions, including Graves' and Hashimoto's diseases, can cause the thyroid -- the butterfly-shaped gland above your collarbone that's responsible for regulating metabolism and body temperature -- to produce too much or too little of certain hormones, leading to weight gain or loss. Other symptoms include fatigue and muscle weakness.
Watch out for: All-over body aches
No one knows what causes fibromyalgia, but it's much more common in women than in men. And it's tough to identify because the symptoms -- sleep problems, headaches, muscle pain, fatigue, trouble concentrating -- could be attributed to many conditions. A 2011 report in Clinical and Experimental Rheumatology noted that fibromyalgia is the second-leading cause of visits to the rheumatologist, yet often takes years to diagnose.