It's natural for men to notice a gradual decrease in sex drive (libido) as they age. The degree of this decline varies. But most men maintain at least some amount of sexual interest into their 60s and 70s.

But sometimes loss of sex drive is related to an underlying condition. Depression, stress, alcoholism, illicit drug use and fatigue often can be factors in loss of sex drive in men.

Sometimes the culprit is a decrease in male sex hormones due to an endocrine disorder. In other cases, loss of sex drive may be a medication side effect.

If you're concerned about loss of sex drive — especially if the loss happened suddenly — talk to your doctor. Your doctor will likely discuss your detailed medical history, do a physical exam and request lab tests to help determine what's causing the loss of sex drive.

After identifying what's causing the loss of sex drive, your doctor can suggest treatment options. For example:

• If loss of sex drive is related to stress or depression, seeing a counselor, sometimes in combination with taking antidepressant medication, might help.

• Some medical conditions, such as obstructive sleep apnea, can cause an unusually low testosterone level. Treating the sleep apnea will reverse the low testosterone level and improve sex drive.

  If a reversible cause for low testosterone isn't found, testosterone replacement therapy might return your testosterone level and sex drive to normal.

• If a certain medication is contributing to loss of sex drive, your doctor might suggest that you take a different drug.

Some people have a hard time discussing sex with their doctors. But treatments are often available for a loss of sex drive, so it's worth it to be open with your doctor.

Some loss of taste and smell is natural with aging, especially after age 60. However, other factors can contribute to loss of taste and smell, including:

• Nasal and sinus problems, such as allergies, sinusitis or nasal polyps
• Certain medications, including beta blockers and angiotensin-converting enzyme (ACE) inhibitors
• Dental problems
• Cigarette smoking
• Head or facial injury or mass
• Alzheimer's disease
• Parkinson's disease

Loss of taste and smell can have a significant impact on quality of life, often leading to decreased appetite and poor nutrition. Sometimes loss of taste and smell contributes to depression. Loss of taste and smell also might tempt you to use excess salt or sugar on your food to enhance the taste — which could be a problem if you have high blood pressure or diabetes.

If you're experiencing loss of taste and smell, consult your doctor. Although you can't reverse age-related loss of taste and smell, some causes of impaired taste and smell are treatable. For example, your doctor might adjust your medications if they're contributing to the problem. Many nasal and sinus conditions and dental problems can be treated as well. If you smoke, quitting can help restore your sense of smell.

If necessary, your doctor might recommend consulting an allergist, an ear, nose and throat specialist (otolaryngologist), a neurologist, or other specialist.

Low amniotic fluid (oligohydramnios) is a condition in which the amniotic fluid measures lower than expected for a baby's gestational age. No treatment has been proved effective long term. But short-term improvement of amniotic fluid is possible and might be done in certain circumstances.

During pregnancy, amniotic fluid provides a cushion that protects the baby from injury and allows room for growth, movement and development. Amniotic fluid also keeps the umbilical cord from being compressed between the baby and the uterine wall. In addition, the amount of amniotic fluid reflects the baby's urine output — a measure of a baby's well-being.

If you have low amniotic fluid, what happens next will depend on the cause, severity, your baby's gestational age, your health and your baby's health.

Various factors can contribute to low amniotic fluid in pregnancy, including:

• Your water breaking
• The placenta peeling away from the inner wall of the uterus — either partially or completely — before delivery (placental abruption)
• Certain health conditions in the mother, such as chronic high blood pressure
• Use of certain medications, such as angiotensin-converting enzyme (ACE) inhibitors
• Certain health conditions in the baby, such as restricted growth or a genetic disorder

If you have low amniotic fluid and you're 36 to 37 weeks pregnant, the safest treatment might be delivery. If you're less than 36 weeks pregnant, your health care provider will review your baby's health, discuss why you might have low amniotic fluid and recommend monitoring your pregnancy with fetal ultrasounds. He or she also might recommend drinking more fluids — especially if you're dehydrated.

If you have low amniotic fluid during labor, your health care provider might consider a procedure in which fluid is placed in the amniotic sac (amnioinfusion). This is typically done during labor if there are fetal heart rate abnormalities. Amnioinfusion is done by introducing saline into the amniotic sac through a catheter placed in the cervix during labor.

Low amniotic fluid during pregnancy is a serious condition. If you have any concerns about the amount of fluid around your baby, talk with your health care provider.

Low blood sodium (hyponatremia) occurs when you have an abnormally low amount of sodium in your blood or when you have too much water in your blood. Low blood sodium is common in older adults, especially those who are hospitalized or living in long-term care facilities.

Signs and symptoms of hyponatremia can include altered personality, lethargy and confusion. Severe hyponatremia can cause seizures, coma and even death.

Hyponatremia is more common in older adults because they're more likely to take medications or have medical conditions that put them at risk of the disorder. These risk factors include:

• Drugs that make you urinate more (diuretics)
• Some types of antidepressants
• Carbamazepine, an anti-seizure medication
• Underactive thyroid or adrenal glands
• Decreased function of the kidneys, liver or heart
• Certain cancers, including lung cancer
• Certain illnesses, such as pneumonia or urinary tract infections, that can cause dehydration

Hyponatremia treatments may include changing a medication that affects your sodium level, treating the underlying disease, changing the amount of water you drink or changing the amount of salt in your diet.

Various factors can cause a low milk supply during breast-feeding, such as waiting too long to start breast-feeding, not breast-feeding often enough, supplementing breastfeeding, an ineffective latch and use of certain medications. Sometimes previous breast surgery affects milk production.

Other factors that can affect milk production include:

• Premature birth
• Maternal obesity
• Pregnancy-induced high blood pressure
• Poorly controlled insulin-dependent diabetes

Although many women worry about low milk supply, insufficient breast milk production is rare. In fact, most women make one-third more breast milk than their babies typically drink.

To boost milk production:

• Breast-feed as soon as possible. Waiting too long to start breast-feeding can contribute to a low milk supply. Hold your baby skin to skin right after birth and your baby will likely breast-feed within the first hour after delivery.
• Breast-feed often. For the first few weeks, breast-feed eight to 12 times a day — about every two to three hours.
• Check your latch. Make sure your baby is latched on and positioned well. Look for signs that your baby is swallowing.
• Be alert to feeding problems. Offer both breasts at each feeding. It's OK for your baby to nurse on only one breast at a feeding occasionally — but if this happens regularly, your milk supply will decrease. You might pump the other breast to relieve pressure and protect your milk supply until your baby begins taking more at each feeding.
• Don't skip breast-feeding sessions. Pump your breasts each time you miss a breast-feeding session to help protect your milk supply.
• Hold off on the pacifier. If you choose to give your baby a pacifier, consider waiting until three or four weeks after birth. This will give you time to establish your milk supply.
• Use medications with caution. Certain medications decrease milk supply, including medications containing pseudoephedrine (Sudafed, Zyrtec D, others). Your health care provider might also caution against certain types of hormonal contraception, at least until breast-feeding is firmly established.
• Avoid alcohol and nicotine. Drinking moderate to heavy amounts of alcohol can decrease milk production. Smoking can have the same effect.

Maintaining your milk supply during breast-feeding is important for your baby's health and growth. If you're concerned about your milk supply or your baby's feedings, talk to your doctor, your baby's doctor or a lactation consultant.

Phosphorus is a mineral that's found naturally in many foods and also added to many processed foods. When you eat foods that have phosphorus in them, most of the phosphorus goes into your blood. Healthy kidneys remove extra phosphorus from the blood.

If your kidneys don't work well, you can develop a high phosphorus level in your blood, putting you at greater risk of heart disease, weak bones, joint pain and even death.

If you need to limit phosphorus

Your phosphorus needs depend on your kidney function. If you have early-stage kidney disease or you're on dialysis, you may need to limit phosphorus. Nearly every food contains some phosphorus, so this can be hard to do.

The best way to limit phosphorus in your diet is to limit foods highest in phosphorus, including:

• Fast foods, foods sold at gas stations, and other packaged and convenience foods
• Processed cheeses, such as American cheese and cheese spreads
• Fresh or frozen meats that have added flavor or fluids to keep them moist
• Cola and pepper-type sodas, many flavored waters, bottled teas, energy or sports drinks, many powdered drink mixes, beer, and wine

The table below gives examples of foods lower in phosphorus that you can substitute for foods higher in phosphorus. Although a food or drink may be low in phosphorus, you still need to watch portion sizes and limit the number of servings you eat or drink each day.

Check food labels carefully

Manufacturers may add phosphorus when processing foods to thicken them, improve taste, prevent discoloration or preserve them. Check food labels to see whether any ingredients contain "phos" in the term. When trying to limit phosphorus, look for foods that don't list "phos" among the ingredients.

Examples of phosphorus food additives include:

• Calcium phosphate
• Disodium phosphate
• Phosphoric acid
• Monopotassium phosphate
• Sodium acid pyrophosphate
• Sodium tripolyphosphate

Fast foods, convenience foods, and processed meats and cheeses contain potentially large amounts of phosphorus.

Seek professional help

For help creating a meal plan that meets your needs, work with a registered dietitian. A dietitian can make sure that you get enough nutrition while following your doctor's medical recommendations.

Because it's difficult to lower phosphorus in your diet, your doctor may recommend a phosphate binder medication to help control the amount of phosphorus your body absorbs from foods.

A lower back tattoo won't necessarily prevent you from having an epidural, a common type of anesthesia, during labor. The exception would be if the tattoo is:

• Raised and scaly
• Red, swollen or oozing fluid — it appears infected
• Recent and the affected skin is still healing

Research on tattoos and epidurals is limited. Theoretical concerns — such as the development of skin cancer in the affected area years later — remain controversial. Actual reports of problems associated with epidurals and lower back tattoos are rare.

If you have a lower back tattoo and decide to have an epidural during labor, the doctor giving the epidural (anesthesiologist) will likely try to insert the needle through skin that isn't tattooed — such as an open area in the tattoo design. If possible, the anesthesiologist might choose a different space along your lower back.

If that isn't possible, the anesthesiologist might nick your skin before inserting the needle. This reduces any possible risk associated with trapping tattoo pigment inside the needle or depositing the pigment into deeper tissues.

Keep in mind that placing a needle through the tattoo might result in a small scar that could alter the appearance of the tattoo.

If you're concerned about the unknowns associated with tattoos and epidurals, you might ask your health care provider about other options for pain relief during labor — such as relaxation exercises, breathing techniques, nitrous oxide, or oral or injected medications.

Yes, lung nodules can be cancerous, though most lung nodules are noncancerous (benign).

Lung nodules — small masses of tissue in the lung — are quite common. They appear as round, white shadows on a chest X-ray or computerized tomography (CT) scan.

Lung nodules are usually about 0.2 inch (5 millimeters) to 1.2 inches (30 millimeters) in size. A larger lung nodule, such as one that's 30 millimeters or larger, is more likely to be cancerous than is a smaller lung nodule.

If your doctor detects a lung nodule on an imaging test, it's helpful to compare your current imaging scan with a previous one. If the nodule on earlier images hasn't changed in size, shape or appearance in two years, it's probably noncancerous.

Noncancerous lung nodules are often caused by previous infections. Noncancerous lung nodules usually require no treatment. In some cases your doctor may recommend annual chest imaging to see if a lung nodule grows or changes over time.

If a lung nodule is new or has changed in size, shape or appearance, your doctor may recommend further testing — such as a CT scan, positron emission tomography (PET) scan, bronchoscopy or tissue biopsy — to determine if it's cancerous.

Unfortunately, yes. Lupus causes widespread inflammation that usually involves your skin — particularly on your face and scalp. Lupus can cause the hair on your scalp to gradually thin out, although a few people lose clumps of hair. Loss of eyebrow, eyelash, beard and body hair also is possible.

In most cases, your hair will grow back when your lupus is treated. But some people with lupus develop round (discoid) lesions on the scalp. Because these discoid lesions scar your hair follicles, they do cause permanent hair loss.

Lupus can also cause the scalp hair along your hairline to become fragile and break off easily, leaving you with a ragged appearance known as lupus hair.

Hair loss may be an early sign of lupus, before the disease is diagnosed. But many other disorders can cause hair loss, so consult with your doctor if you notice unusual hair thinning or hair loss.

Lupus can cause hives, but this is uncommon. The exact cause of hives in lupus isn't clear. But it may be due to certain antibodies produced by some people with lupus. Sun exposure also may play a role. In addition, some of the medications used to treat lupus may cause side effects that include hives.

Individual hives usually last less than 24 hours. Individual hives that last longer than 24 hours may be due to urticarial vasculitis, a condition characterized by inflammation of the small blood vessels in the skin. Lupus is one cause of urticarial vasculitis.

Signs and symptoms of urticarial vasculitis include an itching and burning sensation in the affected skin. Unlike hives, wheals caused by urticarial vasculitis may leave behind a bruise. A doctor may confirm a diagnosis of urticarial vasculitis by a biopsy of the affected skin.

Treatment of hives may include:

• Antihistamines
• H-2 blockers (cimetidine)
• Corticosteroids

Treatment of urticarial vasculitis also may include antihistamines, H-2 blockers and corticosteroids, but used for a longer time than with simple hives. Aggravating factors, such as sun exposure, also may need to be controlled.