Guest Post, Health

The Flu: An Overview

By Aparna Mani, MD, PhD
MGH Medical Walk-In Unit

Aparna Mani, MD, PhD

It seems like every year come winter we’re inundated with health care providers’ recommendations and public service campaigns to get the flu vaccine. But what exactly is the flu and why is it such a big deal? ‘Flu’ is short for influenza, an infectious disease caused by a small group of viruses – namely influenza virus A, influenza virus B and influenza virus C. These viruses target and infect the respiratory tract (nose, throat and lungs) causing the illness we call the flu. People with the flu experience a combination of high fever, chills, sore throat, significant fatigue, muscle aches, headache, and cough. True, many of these same symptoms are associated with the common cold, but colds are caused by a different set of viruses and these symptoms are much less severe (and much shorter in duration) than with the flu.

One reason there is so much public attention given to the flu is its potential to cause large-scale outbreaks. In fact in 1918 a particularly lethal flu pandemic spread through many parts of the world, resulting in an estimated 500 million deaths. Though we have not seen as high a fatality rate from the flu in recent memory, and even though most healthy individuals will completely recover from the flu in about one to two weeks, it’s still a highly contagious illness that has the potential to turn particularly severe (and potentially deadly) in certain populations. The CDC estimates that approximately 3,000 to 49, 000 people have died from the flu each year over the past 30 years. This is the driving force behind the recommendation for the flu vaccine.

The Flu Vaccine

Each year the World Health Organization researches and identifies the strains of influenza viruses they predict will cause the bulk of the flu illness for the upcoming season.  Based on these predictions vaccine manufacturers develop the seasonal flu vaccine, which is made available to the public starting in the fall.  Why does a brand new vaccine need to be developed each year? The influenza viruses, influenza A in particular, have a high rate of mutation. This means that they’re able to change a component of themselves, one of their viral “body parts” as it were, to such a degree that the immune system is unable to remember prior versions of the virus. Put another way, someone who had the flu last year may build up immune defenses against the strain of virus that caused their illness, but those defenses may not recognize a new or different version of the virus this year. Thus, the flu vaccine given this season is no longer protective for the next.  This is also why some individuals may still get the flu despite having gotten a flu shot:  they may have gotten infected with a strain of the virus that was not included in the vaccine.  There are two forms of influenza vaccine available: an injectable version commonly known as the “flu shot” and a nasal vaccine which is sprayed into the nose.  You cannot get the flu illness from either of these vaccines themselves. The virus used to make the injectable vaccine is inactivated or killed while the virus used to make the nasal version is attenuated or weakened.

Potential Complications, Treatment and Prevention

So how does a virus that causes sore throat, muscle ache, fever, chills, headache and cough become deadly? Well, some individuals can develop an infection of the lung or pneumonia caused by the influenza virus itself, or by bacteria that began growing in the lungs while the immune system was busy dealing with the flu virus.  Babies under the age of 2, pregnant women, and people over 65 are most susceptible to this complication.  People who are immunocompromised (have a weakened or no immune system) from another illness, who smoke, or have a chronic illness such as asthma, diabetes, lung or heart disease are also at risk for severe complications.

What happens when someone gets the flu?  Depending on the severity of symptoms and any complicating medical conditions, healthcare providers may prescribe an oral antiviral medication. Though these medications do not cure the flu, they may decrease the severity and duration of symptoms as well as the chance of developing complications.  The CDC recommends such treatment for specific populations, including hospitalized patients and people at high risk for complications including children under 2; adults over 65; pregnant or postpartum women; residents of nursing homes; immunosuppressed individuals; and those with chronic illnesses.  For anyone not included in the above populations, flu symptoms can be effectively treated with some over the counter medications. Acetaminophen or ibuprofen can help to reduce fever, headache and muscle aches.  Aspirin or other salicylates should be avoided, especially in children under 18, as it has been associated with Reye syndrome. In addition, people with the flu should drink plenty of fluids and get a good amount of rest. Flu symptoms may last for one week or more.

As with anything, prevention is the best course of action.  Flu viruses are highly contagious through contact with contaminated surfaces and through the air, so habits such as hand washing with soap and water, covering one’s mouth when coughing or sneezing, and avoiding touching the eyes, nose and mouth limit its spread and transmission.  Good hygiene and annual vaccination are the best defenses against the flu.

Diabetes ABCs

Diabetes ABCs: R



Retinopathy is a common complication of diabetes that affects the retina—the part of the  eye that creates pictures of what we see.  In some cases, blood vessels in the retina begin to swell or leak; in other cases, fragile new blood vessels develop along this part of the eye.  Either case can cause changes in vision and in extreme cases blindness.  The American Diabetes Association recommends getting an eye exam every year to check for signs of retinopathy and other eye complications.  Early detection can make treatment more effective.  Keeping your blood sugar in good control can reduce your chances of developing retinopathy.

(Content reviewed by MGH Diabetes Center)
Diabetes ABCs

Diabetes ABCs: N



Neuropathy is damage to the nerves, the fibers used to transmit messages from the brain to other parts of the body.  A common complication of diabetes, diabetic neuropathy can develop over time as high blood sugar damages nerve fibers.  Neuropathy can affect all parts of the body but peripheral neuropathy, the most common form of diabetic neuropathy, affects the feet, legs, arms and hands.  Symptoms can include tingling or numbness, difficulty feeling hot/cold, pain and sensitivity to touch.  Keeping your blood sugar in good control can help prevent developing or worsening neuropathy.

(Content reviewed by MGH Diabetes Center)
Diabetes ABCs

Diabetes ABCs: D

Diabetic ketoacidosis
by Eileen B. Wyner, NP
Bulfinch Medical Group Letter D

Diabetic ketoacidosis occurs when the body cannot use sugar (glucose) as a fuel source because there is no (or not enough) insulin. Fat is used for fuel instead and the byproducts of this fat breakdown, called ketones, build up in the body. This is a potentially life threatening condition that can happen in both Type 1 and Type 2 Diabetes, although it is very rare in the latter. Symptoms may include fatigue, fruity breath, stomach pain, nausea and vomiting, and blood sugar greater than 300 mg/dL. Immediate medical attention is required to treat these symptoms.

Dawn Phenomenon
by Eileen B. Wyner, NP
Bulfinch Medical Group

This phenomenon is one factor responsible for morning hyperglycemia in people with both Type 1 and Type 2 Diabetes. It also occurs in people without diabetes. It is caused by the early morning (4 a.m. to 8 a.m.) surge of hormones such as growth hormone and cortisol. The hyperglycemia in people with diabetes is a result of insufficient insulin production required to maintain normal blood glucose values.


Diabetic Nephropathy

By Eileen B. Wyner, NP
Bulfinch Medical GroupEileen W

Diabetic Nephropathy (DN) or kidney disease is a potential complication of Diabetes. It may occur in people who have been living with Diabetes for a long time, as well as in people whose Diabetes is poorly controlled.  All people with Diabetes are at risk for DN but it appears that risk may be higher for people who are of Hispanic, African American, or Native American ethnicity.   

We are born with two kidneys which are responsible for several important bodily functions, the most well known being the making of urine (necessary for the removal of waste products from the bloodstream).  The kidneys also help to control blood pressure by regulating our water and mineral balance (also known as our electrolyte balance), and maintain red blood cell count by signaling the bone marrow to increase production of these cells.  Kidney disease occurs when blood sugars are continually too high. The filter system in the kidneys becomes damaged, allowing small amounts of protein to leak out through the urine. This is a painless condition without any symptoms at first, but over time will lead to high or hard to control blood pressure and lower extremity swelling if not treated.

The first step in preventing DN is maintaining good blood sugar control—the closer to goal you can keep your A1C safely, the better it is for your kidneys.  The next step is getting a microalbumin test when you see your health care provider.  This test checks for the presence of a protein called albumin in the urine.  Albumin is normally found in the blood and filtered by the kidneys; when kidneys are working properly albumin is not found in the urine.  When the kidneys are damaged, small amounts of albumin leak out into the urine.  This condition is called microalbuminuria.  The American Diabetes Association recommends receiving a microalbumin test at diagnosis and at least annually afterwards.

Managing elevated microalbuminuria includes working hard at getting your A1C to goal and starting a medication from the class ACE or ARB.  You may know these medications by their common names:  lisinopril or diovan. These medications are used for blood pressure control and are also a good choice for protecting your kidneys.  You may already be on one of these medications and the dose may need to be adjusted as needed.

Long term complications of DN can increase your chance of developing heart or blood vessel disease. Your kidneys may fail and you may need to start dialysis to filter your blood.  You may even need a kidney transplant. There is no cure for DN, however early identification and treatment can decrease worsening complications. When you go for your next Diabetes appointment, ask your health care provider about a microalbumin test to check your kidney status and start working on preserving it.