
While our body can detect many health ailments and inform us there's a problem we need to address by pain, there are deadly diseases that are virtually symptom-free. There are little to no warning signs with many hidden health problems, but seeing your doctor annually and taking preventive measures like yearly screenings can make a difference between life and death. Eat This, Not That! Health talked to doctors who explained what a few "silent killer" diseases are and symptoms to watch out for. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.
Brain Tumor

Dr.Santosh Kesari, MD, Ph.D., neuro-oncologist and director of neuro-oncology at Providence Saint John's Health Center and chair of the Department of Translational Neurosciences and Neurotherapeutics at Saint John's Cancer Institute in Santa Monica, CA explains, "The most silent symptom is no symptoms at all. These patients are usually those that undergo a scan for another reason such as unrelated trauma and get a CT or MRI that shows a mass in the brain. The more acute and severe the symptom is, the more likely that the tumor developed quickly and thus higher level of severity."
Brain Tumor Symptoms

There's over 120 different types of brain tumors, according to John Hopkins Medicine, and 30 people out of every 100,000 can develop one. Brain tumors are dangerous because they apply pressure to healthy parts of the brain and become cancerous. Below are signs of a brain tumor to watch out for, says Dr. Kesari.
"Memory Changes: Patients can present with forgetfulness, short term memory loss and usually suggest involvement of temporal or frontal lobes of the brain where memory functions reside. Sometimes can occur over months to years and is thought to have a dementia condition before imaging is done to reveal a brain tumor.
Headaches: Headaches are very common and difficult to associate with tumors. But changes in frequency, type or intensity of headache should prompt neurological evaluation. Headaches typically are due to the tumor size and growth rate. So larger tumors and faster growing tumors cause an increased pressure in the brain resulting in activation of pain receptors on the coverings of the brain (meninges) resulting in headache. The brain itself has no pain receptors. A small fast growing tumor can cause as severe a headache as a large but slow growing tumor.
Weakness: If a brain tumor in the frontal lobe motor cortex or affects the motor fibers (these are the neurons and pathways that control the muscles) then patients can present with weakness of an extremity. This usually indicates the location of the tumor as well.
Personality Changes: Patients present with change in behavior including disinhibition presenting as risky behaviors, or apathy and doing less than they normally would. Patients may not be as effective at job or home functions. These patients usually have tumors in the frontal lobe where executive functions reside.
Vision Changes: Patients may or may not be aware of vision loss with brain tumors. They may keep bumping into things on the side of the body related to the vision loss and/or have repeated car accidents on the side of the loss.
Speech Changes: Patients may present slurred/thick speech or have fluent but gibberish speech that makes no sense to the listener. This is due to the tumor affecting the speech areas in temporal or parietal lobes.
Gait Difficulty: Generally related to affecting the frontal lobe of cerebellum but can also be affected when the motor fibers in the frontal lobe are affected.
Dizziness: Generally non-specific in terms of location but most commonly if tumor in base of brain called the brainstem or affecting cranial nerve 8.
Hearing Changes: This occurs due to tumors affecting the 8th cranial nerve and can result in hearing loss, ringing the ear and also vertigo."
Anal Cancer

Although anal cancer isn't common, the number of people dying from it is rising, according to Cancer.gov. The site states, "About 9,440 new cases ( 3,150 in men and 6,290 in women) [and] "About 1,670 deaths (930 in women and 740 in men)," but added treatment is "effective." Cancer.gov also explained who is at risk. "The number of new anal cancer cases has been rising for many years. Anal cancer is rare in people younger than 35 and is found mainly in older adults, with an average age being in the early 60s. It is also more common in white women and black men." Dr. Jack Jacoub, MD, medical oncologist and medical director of MemorialCare Cancer Institute at Orange Coast Medical Center in Fountain Valley, CA says, "The most common signs and symptoms that men often ignore include pain during defecation, change in bowel habits, blood when wiping, sense of fullness and a lump in that specific area."
Male Breast Cancer

Dr. Przemysław Twardowski, M.D., Medical Oncologist and Professor of Medical Oncology and Director of Clinical Research in the Department of Urology and Urologic Oncology at Saint John's Cancer Institute at Providence Saint John's Health Center in Santa Monica, CA explains, "Male breast cancer is rarely talked about. It accounts for 1 % of all cancer. Risk factors are genetic disposition such as BRCA mutation carrier, excessive estrogen stimulation (from estrogen-containing compounds or testosterone), liver disease, obesity, marijuana use, thyroid disease, or Klinefelter syndrome (hereditary disorder)."
Male Breast Cancer Signs

"Signs of breast cancer are similar to women but often overlooked and minimized by patients and their physicians due to male sex," Dr. Twardowski states. "They include a lump in the breast and/or armpit, breast skin discoloration or ulceration, nipple bleeding, discharge or inversion, skin dimpling or pain if a tumor extends to the chest. If any of these are present seek physician care and get an mammogram, ultrasound and biopsy if indicated ASAP. Lastly, men with excessive breast tissue (gynecomastia) should consider undergoing breast cancer screening yearly."
Testicular Cancer

Dr. S. Adam Ramin, MD, urologist and medical director of Urology Cancer Specialists in Los Angeles says, "Breaking down the walls of this typically 'taboo' topic, a current media spotlight on testicular cancer has begun to widely open the conversation for both men and women, about the nondiscriminatory and very real risk for men of developing it. It's an easy subject to sweep under the rug, since it can be less than comfortable for a majority of men to talk about. But the risk remains and affects every man, regardless of social status, career, or even their relative level of 'health.'"
Why Testicular Cancer is Difficult to Diagnosis

Dr. Ramin says, "The tricky part of spotting these symptoms is that (for the most part) they are subtle. Most men are alerted by pain, 'If it doesn't hurt, nothing's wrong.' For testicular cancer, this is the number one misconception, as the most common symptoms occur without pain. Encouraging the men in your life to do a monthly testicular self-exam is the best way to bring attention to painless symptoms like a change in the size of one testicle, a painless bump or lump, or fluid gathering around the scrotum. However, it's important to note that a small percentage of men (10-20%) initially complain of symptoms unrelated to the testicles. These include stomachaches, backaches, and coughing. And though they may seem like nothing but a common illness, they can indicate that the cancer has already advanced. Men may sometimes even experience breast or nipple tenderness, or an increase in breast size as a testicular cancer symptom. When faced with any of these symptoms, have your husband, son, or friend give themselves an extra examination to double check for lumps and then see a doctor."
Testicular Cancer Signs

Symptoms to watch out for include, Dr. Ramin states,
- "A dull ache in your abdomen or groin
As the tumor grows, one will experience a dull ache in the groin or lower abdomen.
- Tenderness in your breasts.
Some testis tumors produce a female hormone called Beta HCG. This hormone may cause breast growth, pain tenderness.
- Heaviness in your scrotum
In some cases of testis cancer, a large amount of fluid develops around the testis with cancer. This reactive fluid causes progressive enlargement of the scrotum, which in turn results in a heaviness feeling in the area.
- A sudden collection of fluid in your scrotum." And to protect your life and the lives of others, don't visit any of these 35 Places You're Most Likely to Catch COVID.