If you’re suffering from common symptoms, such as fatigue, frequent colds or poor sleep, but your doctor can’t identify a cause, don’t give up.

Problem: Widely used medical tests can’t always uncover the cause of so-called “nonspecific symptoms,” and some doctors are too quick to chalk them up to mental health problems.

Solution: The root cause of your symptoms may be a nutritional deficiency or some other easily treatable condition. Your best bet to identify the cause of unexplained symptoms is to work with a physician trained in complementary medicine, which relies on diagnostic techniques and therapies that complement doctors’ standard care.* Common—and treatable—problems that are often overlooked…

NUTRIENT IMBALANCES

Obvious nutritional problems, such as a deficiency of thiamin or iron, can be diagnosed with standard blood tests. However, more subtle imbalances of different nutrients cannot. Even if your nutrient levels are in the normal range, you might need less or more of a particular nutrient than someone else.

Common symptoms of nutrient imbalances: Mood swings, fatigue, anxiety and depression often occur with deficiencies of B vitamins. Brittle nails often indicate a nutritional imbalance, such as low calcium, zinc or iron.

How to find the real culprit: In addition to blood tests that can measure levels of vitamins, minerals and amino acids, I perform a functional nutrient assessment, a specialized blood test that measures enzymes and other substances that are affected by particular nutrients. This test tells doctors whether nutrients are getting to the cellular level and doing their job.

Important: Conventional doctors look at averages. For example, a normal (average) level of vitamin B-12 is 200 picograms per milliliter (pg/mL) of blood to 900 pg/mL. But it’s not uncommon for patients to start having symptoms, such as anxiety, when B-12 drops below 400 pg/mL.

Best treatments: Most nutritional imbalances and/or deficiencies can be treated with dietary changes alone. For example, low levels of zinc often can be corrected by eating more zinc-rich foods, such as shellfish and pumpkin seeds. Your doctor may also recommend supplements to correct a deficiency.

Caution: If you frequently take heartburn medication that suppresses stomach acid, such as omeprazole (Prilosec) or over-the-counter antacids, you should expect nutritional imbalances. These heartburn medications may impair the body’s ability to absorb zinc, calcium, magnesium and other vital nutrients. For this reason, I recommend that my patients who take these drugs receive annual blood tests to measure their levels of key nutrients and take supplements as needed to correct any deficiencies.

MITOCHONDRIAL DYSFUNCTION

Every function in the body, from the beating of the heart to muscle movements and brain functions, depends on healthy mitochondria, the “power plants” inside cells.

Patients who have been exposed to environmental toxins, such as industrial chemicals, may have low energy because of damaged mitochondria. Some neurological diseases, such as multiple sclerosis, also have been linked to damaged mitochondria.

Common symptoms of mitochondrial dysfunction: Fatigue, shortness of breath and sometimes symptoms such as muscle weakness or shaking.

How to find the real culprit: Blood and urine testing to measure metabolites, small molecules that are formed by the normal breakdown of organic compounds in the body. Patients with a mitochondrial disorder will have metabolite levels that are lower or higher than normal.

Best treatments: Try to reduce your exposure to all chemicals. For example, use natural cleaning products in the home, such as baking soda and vinegar…or green products, such as those made by Seventh Generation, Ecover and Green Works. Avoid cleaning products, such as Lysol and Fantastik, that contain solvents that can trigger headaches, dizziness and congestion. Also, stay away from chemical-based pesticides, and use glass instead of plastic containers to avoid exposure to bisphenol A, an industrial chemical commonly used in plastic water and food containers.

Supplementing with coenzyme Q10 (CoQ10) can help repair mitochondrial damage. Dose: 50 mg to 200 mg daily, depending on the patient.

Important: Statins can damage mitochondria and deplete CoQ10 from the body. If you take one of these drugs, ask your doctor about taking a CoQ10 supplement. Caution: While some small-scale studies suggest that CoQ10 may benefit the heart in patients undergoing chemotherapy, other studies have found that CoQ10 may reduce the effectiveness of some chemotherapy drugs and blood thinners. Talk to your doctor.

IMMUNE IMBALANCE

Patients who get frequent infections, including colds, often have irregularities in the immune system that cause it to be underactive. This can be due to both physical and emotional stress.

Common symptoms of immune dysfunction: A patient might suffer from frequent yeast infections or a higher-than-expected number of colds.

How to find the real culprit: Blood tests to measure levels of different immune cells, including T and B cells and natural killer cells.

Best treatments: Most patients with underactive immunity will improve when they exercise more and eat a healthful diet with lots of garlic…fresh fruits, including blueberries, strawberries and raspberries…and vegetables, especially kale, spinach, broccoli, kohlrabi, squash, mushrooms, onions, and red, yellow and orange peppers.

Also helpful: Supplementing with beta-1,3-glucan, a sugar derived from the cell wall of brewer’s yeast. It stabilizes the immune system and improves its ability to fight infections. Dose: 100 mg to 400 mg daily.

In some patients, the immune system may also be improved with vitamin C (500 mg to 1,500 mg daily)…zinc (15 mg to 30 mg daily)…and the immune-boosting herb ashwagandha (300 mg daily). Check with your doctor before taking these or any other supplements.

TOXICITY

It’s among the main causes of unexplained symptoms. People often think of “toxins” as industrial pollutants, but we’re all exposed to toxins in our homes and workplaces from new carpets, fresh paint, etc.

Common symptoms of toxicity: Poor sleep, lethargy, headaches and/or unexplained aches and pains.

How to find the real culprit: Blood tests to check liver enzymes and urine testing to determine how effectively your body is removing toxins. We can also measure levels of solvents, pesticides and metals in the blood. These contribute to toxicity in the body.

Best treatments: Avoiding toxic chemicals is the best approach. Also consider a sauna detox—the skin is an effective organ for eliminating toxins. What to do: Take a 30-minute sauna, two or three times a week. If you don’t have access to a sauna, add a cup of Epsom salts to a warm bath to help draw out toxins. Caution: If you have heart disease, high blood pressure or arrhythmias, check with your doctor before using a sauna. Chelation is another option. This procedure involves the use of drugs that bind to heavy metals in the blood so that they may be excreted in the urine. It is especially effective for removing such metals as lead and mercury.

In addition, the herbal remedy milk thistle extract contains silymarin, a compound that cleanses the liver and removes toxins. Dose: About 200 mg, two to three times daily. Caution: If you take an antiseizure, antianxiety or allergy drug or cholesterol-lowering or cancer medication, or a blood thinner, be sure to talk to your doctor before taking milk thistle.

Also helpful: Two to three cups of green tea daily. It has liver-cleansing properties.

*Check with your health insurer to determine whether the cost of such tests is covered by your policy. To find a physician who uses complementary medicine, check the Web site of the American College for Advancement in Medicine, www.acamnet.org.