Many people wonder whether to proceed with scheduled blood work when feeling unwell. This often involves weighing the need for diagnostic information against the possibility that current symptoms might influence test results. There’s also the question of whether visiting a lab while sick is appropriate, considering potential impacts on test accuracy and public health.
General Guidance for Blood Tests While Unwell
Deciding whether to get blood tests while unwell depends on several factors: the nature and severity of your illness, and the test’s purpose. In some situations, proceeding is advisable; in others, postponing yields more accurate results. Understanding these nuances helps you make an informed decision.
How Illness Can Impact Test Results
Illness can significantly alter blood markers, leading to inaccurate test results. For example, the body’s inflammatory response to infection often elevates acute phase reactants like C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). While these indicate inflammation, their elevation from a transient illness can obscure other conditions or lead to misinterpretations.
Dehydration, common with fever, vomiting, or diarrhea, can also skew results. When fluids are insufficient, blood components concentrate, affecting electrolyte levels (sodium, potassium) and kidney function indicators (BUN, creatinine). Stress from illness can elevate blood glucose levels due to cortisol release, complicating metabolic health assessment. Illness can also influence liver enzyme levels or complete blood count (CBC) readings, making baseline interpretation challenging. For instance, a bacterial infection can elevate white blood cell (WBC) count, while viral infections may lower it.
Situations Where It’s Usually Okay to Get Tested
In some cases, blood work while mildly unwell is acceptable or necessary. For chronic conditions, routine check-ups are crucial for monitoring disease progression or medication effectiveness. Mild symptoms like a runny nose or minor cough, without fever or significant body aches, usually don’t affect most routine blood tests.
Urgent situations may also require immediate blood work. If a healthcare provider suspects an acute condition needing prompt diagnosis, such as appendicitis or a severe infection, obtaining tests quickly is essential. Here, rapid diagnosis and treatment benefits outweigh minor variations from mild illness.
Situations Where Postponing is Recommended
Conversely, delaying blood work is often advisable for accurate results and to prevent complications. Acute infections with fever, body aches, or severe respiratory symptoms can significantly impact blood parameters. GI illnesses with nausea, vomiting, or diarrhea often cause dehydration and electrolyte imbalances, skewing kidney function and fluid balance tests.
If the illness affects the organ system being evaluated (e.g., viral infection causing liver inflammation before liver function tests), postponing is prudent. Delaying non-urgent tests until recovery ensures results reflect your baseline health. This minimizes misdiagnosis or unnecessary follow-up due to temporary physiological changes. It is often recommended to wait until you feel better, plus at least another couple of days, to ensure results are not skewed by the body fighting off an infection.
Essential Communication Before Testing
Clear communication with your healthcare provider is paramount before any blood draw. Always inform your doctor or lab staff about any symptoms, even minor ones, and all medications you are taking. This includes over-the-counter drugs, supplements, and prescriptions.
This information allows medical professionals to accurately interpret your results, considering your current health. They can advise if proceeding is appropriate or if rescheduling would yield more reliable data. This proactive communication ensures your blood work provides the most meaningful health insights.