DEAR DOCTOR K: My blood pressure has been creeping up lately, so my doctor suggested I reduce the amount of salt in my diet. Where should I start?

DEAR READER: That's good advice - and it's good advice for most people, especially for people with high blood pressure. Cutting back on salt (sodium chloride) lowers blood pressure and saves lives. Aim to limit your daily sodium intake to no more than 2,300 milligrams (about a teaspoon) per day.

How do you do that? Start reading food labels to find out how much sodium is in the foods you eat. That's the easy part. Of course, if you're eating out, it's harder.

Some chain restaurant and fast-food meals can top 5,000 milligrams of sodium per serving - that's more than an entire day's recommended sodium intake. Check restaurant websites for sodium information, or ask your server to steer you to low-salt choices.

In some cases it's not hard to tell which foods to avoid. Certain foods are inherently high in sodium, so go light on them. Some of the biggest culprits are pizza with meat toppings, processed cheese, hot dogs, salami and spaghetti with sauce. Even white bread has a lot of sodium in it.

Watch out for hidden sodium, too. Some foods that are high in sodium may not taste especially salty. Examples include breakfast cereals, bakery muffins, energy and sports drinks.

Avoid processed and prepared foods such as cold cuts and canned vegetables. These are the biggest sources of sodium in our diets. Choose fresh and minimally processed foods instead.

If you can't eliminate processed foods entirely, then compare brands to find the ones with the least sodium. There's a surprising amount of variation from brand to brand.

Also pay attention to potassium. In contrast to sodium, more potassium in your diet helps keep blood pressure in check. Many fruits and vegetables, like bananas, oranges and grapefruit, are naturally low in sodium and are good sources of potassium.

Retrain your taste buds to enjoy foods with less sodium. Reduce salt gradually and consistently, rather than trying to cut back by a large amount all at once. As time goes on, you won't miss the salt. I used to sprinkle lots of salt on nearly everything I ate (no, not on apple pie). After gradually using less salt over several months, the same foods I used to put salt on taste great without it.

Some people are born to be more sensitive to salt, and salt in their diet is more likely to raise their blood pressure. There is no easy way to know if you are one of those people, but there is an easy way to measure your blood pressure. Particularly if your doctor has ever told you that your blood pressure was high or borderline high, talk to him or her about using a home blood pressure machine. It is simple to use and accurate.

We have more information on preventing high blood pressure in our Special Health Report, "Hypertension: Controlling the Silent Killer." You can find out more about it at my website.

Dr. Komaroff is a physician and professor at Harvard Medical School. Go to his website to send questions and get additional information: www.AskDoctorK.com.