Hello again, dear readers, and welcome to our monthly column devoted to your thoughts, notes and suggestions. We’re deep into spring, so here’s our annual reminder to be on high alert for ticks. Dress defensively, use repellents and do thorough and regular tick checks. Always seek medical care if a tick bite is followed by a rash, fever or other flulike symptoms. Be sure to also protect any four-footed companions with access to the outdoors. And now, to the inbox.

-- Many of you wrote in response to a column about the health benefits of nuts, asking if roasted and salted nuts are OK. Although roasting doesn’t affect protein, fiber or carbohydrate content, it may chemically alter the healthy fats that nuts contain. Roasting can also cause the formation of acrylamide, a compound that has been studied as a potential carcinogen. Roasted nuts have less acrylamide than potato chips or french fries, and the American Cancer Society says the effect on cancer risk in humans remains unclear. Regarding salted nuts, the main caution is to include the added sodium in calculating your total daily intake. This shouldn’t exceed 2,300 milligrams, and is hopefully closer to the American Heart Association’s goal of 1,500 milligrams per day.

-- Regarding a column about sexually transmitted diseases, a reader asked whether washing or douching after sex will protect against sexually transmitted diseases. The answer to both of those is NO. The best protection against STDs is the correct and consistent use of latex condoms, which can prevent transmission of both bacterial and viral STDs.

Although topical microbicides, which are substances like gels, films or suppositories, can kill or neutralize viruses and bacteria, it is recommended they be used along with condoms. Since some STDs can be transmitted via oral sex, it’s important to have a frank conversation about sexual history and potential health risks with your partner before sex.

-- We heard from a lot of parents in response to the column about the potential problems caused by the heavy school backpacks our kids are now toting. One reader wishes we had gone into more detail about how to lighten the load.

“This is a good time to teach children how to plan and decide what to keep in their backpack all the time versus what they need at certain periods of the day,” she wrote. “Many keep everything just because they might need it. Teaching them planning, time management and simple solutions like rotating books and binders during their day, or sharing binders for several morning or afternoon classes, can lighten the load.”

-- When we write about dogs, we get a ton of mail. In response to a recent column about a grandfather’s plans to adopt a dog, a reader from Oklahoma pointed out that pets aren’t for everyone: “If the person has balance problems or vision problems, there could be a high likelihood of tripping over the pet,” he wrote. “That could result in some serious injury.”

Thank you, as always, for your interest and engagement with this column. We love hearing from you and look forward to your letters.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: My second husband and I have tried to get pregnant for over a year now, but we have had no luck. Should we be worried about infertility? I’m the mother of a 2-year-old girl and a 4-year-old boy, so the problem probably isn’t with me. What causes that in a man?

Dear Reader: When a woman and man have not achieved pregnancy after a year of regular unprotected sex, they meet the clinical definition of infertility.

You and your husband may feel as though you’re alone in this, but studies suggest that up to 15% of couples are unable to conceive in the first year of trying. About one-third of the time, infertility is due to issues with the man; one-third of the time, it’s issues with the woman; and in the remaining cases, the problem lies in an often-complex mix of issues with both partners. In some cases, the cause of infertility cannot be identified.

For men, the most common causes of infertility are tied to problems with sperm production and sperm motility. These can arise as a result of health problems like diabetes; previous infections such as the mumps or HIV; hormonal problems, including low testosterone; various genetic issues; sexually transmitted diseases; autoimmune disorders; and even lifestyle factors such as smoking, drinking, illicit drug use or steroid use. Some men have blockages in their reproductive systems that can range from partial to total, and that can affect the sperm count. These can be present from birth, or they can develop as the result of physical trauma.

Swollen veins in the scrotum, known as varicoceles, can have a negative effect on sperm growth. These are present in up to 40% of men with infertility problems. A condition known as retrograde ejaculation, which prevents sperm from exiting via the penis and sends it to the bladder instead, can result in infertility in men with normal sperm counts.

Certain medications can change sperm production, function and delivery, including those used to treat depression, infection, high blood pressure and arthritis. Chemotherapy and radiation treatments can also affect male fertility. The causes of male infertility are numerous and varied -- our list is nowhere near complete -- and addressing the issue requires medical assistance.

Diagnosis begins with a physical exam, which will include a detailed medical history. Your husband will be asked about chronic health conditions, past health problems or injuries, prior surgeries and environmental or lifestyle factors. In addition to those already mentioned, they can include obesity, stress, age and diet.

Knowing one’s family history helps to identify inherited conditions. Your husband will also be asked for a semen sample to assess sperm count, structure, motility and concentration. If the semen analysis finds no problems with the sperm, then further testing is needed. This can include hormone tests, scans of the testicles and scrotum to visualize possible blockages, and post-ejaculation urinalysis to look for sperm in the urine. Treatment depends on the results of the tests. Hormone therapy helps to address low testosterone. Surgery can often successfully remove blockages.

Unfortunately, diagnosing male infertility is challenging and a definitive answer is not always found.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)

Dear Doctor: We have a dear friend who is 46 and has alcoholism. His liver is failing, but he blames that and all of his symptoms (fatigue, burning lungs, severe stomach pain, sinus problems, confusion) on factors besides his drinking. What are the long-term effects of abusing alcohol?

Dear Reader: Alcoholism is a disorder in which an individual has lost the ability to regulate their drinking, even though the habit is clearly causing harm. A diagnosis of an alcohol use disorder means someone has met at least two of a series of criteria within a one-year period. These behaviors, which have been laid out by the American Psychiatric Association, include a need to keep drinking despite clear evidence of self-harm; increasing tolerance to the effects of alcohol; physical symptoms when alcohol is withheld; an inability to limit the amount one drinks; losing large chunks of time to planning, seeking, consuming and recovering from drinking; and withdrawal from the activities of daily life. The more criteria that are met, the more severe the problem.

Risk factors for an alcohol abuse disorder range from stress, trauma, peer pressure, ease of access, depression and other emotional issues, to genetic factors, the age at which someone starts drinking and family history. And as your letter attests, the drinker is rarely the only one harmed by an alcohol use disorder. The effects are far-reaching and can interfere with a person’s family, social, work and spiritual lives.

Regarding the variety of physical symptoms your friend has experienced, it’s not possible to know the cause without a physical exam and diagnostic tests. However, many of them do correspond to symptoms that accompany alcohol abuse. As anyone who has ever had a drink too many knows, the short-term effects of alcohol use can include slurred speech, impaired coordination, impaired judgment, changes to mood, diarrhea, vomiting, headache, dehydration and memory lapses.

Long-term alcohol abuse adversely affects virtually every part of the body. Chronic heavy drinking can weaken the heart muscles, contribute to high blood pressure, cause irregular heartbeat and raise the risk of stroke. It can also lead to serious and persistent changes to the structures and functioning of the brain. Although heavy drinking is most associated with liver damage, including the irreversible destruction and scarring of liver tissue known as cirrhosis, it also causes a range of digestive problems. These include ulcers in the stomach or esophagus, inflammation of the pancreas and inflammation of the stomach lining.

Because alcohol interferes with the release of glucose from the liver, low blood sugar becomes a risk. This makes heavy drinking particularly dangerous for anyone with diabetes. A number of studies have linked long-term alcohol abuse to increased risk of certain cancers, including liver, colon, throat, mouth, larynx and rectum. Even moderate drinking has been linked to an increase in the risk of breast cancer.

Unfortunately, the denial that you describe is also often part of alcohol use disorder. If you decide to talk to your friend about his drinking, you’ll find guidance and support from a number of well-regarded organizations, including the National Institute of Alcohol Abuse and Alcoholism (NIAAA), and Alcoholics Anonymous.

(Send your questions to askthedoctors@mednet.ucla.edu, or write: Ask the Doctors, c/o UCLA Health Sciences Media Relations, 10880 Wilshire Blvd., Suite 1450, Los Angeles, CA, 90024. Owing to the volume of mail, personal replies cannot be provided.)