The feeling of sickness while breastfeeding is a common concern that often leads parents to question the safety of continuing to nurse. It is important to distinguish between a general illness contracted outside of the process and symptoms that arise directly from the demands of milk production. Breast milk itself rarely causes illness in the infant; in fact, it provides protective benefits. However, the physical act of lactation can lead to conditions that make the nursing parent feel genuinely unwell.
Lactation-Specific Causes of Maternal Illness
One of the most frequent causes of feeling unwell specific to nursing is mastitis, an inflammation of the breast tissue that may or may not involve a bacterial infection. This condition often begins when a milk duct becomes blocked, causing milk to back up and leading to inflammation. Symptoms often appear suddenly and can mimic a severe flu, including a fever of 101°F or higher, body aches, chills, and fatigue.
The breast tissue may become swollen, warm to the touch, and painful, sometimes showing a wedge-shaped area of redness. Bacterial infection, often caused by microbes from the skin or the baby’s mouth entering through a cracked nipple, can worsen these symptoms. Continuing to empty the affected breast, whether through nursing or pumping, is an important part of treatment and is safe for the infant, even when antibiotics are prescribed.
Another localized issue is breast thrush, a fungal infection caused by the organism Candida albicans. Thrush is often linked to recent antibiotic use in either the parent or baby, or to damaged nipple tissue. The pain is typically described as a burning, stinging, or deep shooting sensation within the breast, usually in both breasts, and often persists for up to an hour after a feeding ends.
Unlike mastitis, thrush generally does not cause a fever or flu-like systemic symptoms. Since the fungus can pass back and forth between the parent’s nipples and the baby’s mouth, both must be treated simultaneously to clear the infection. Pain that does not resolve with improved positioning should prompt an evaluation for a fungal infection.
Transmission of Systemic Infections Through Milk
When a nursing parent contracts a common systemic illness like a cold, influenza, or a typical stomach bug, the recommendation is to continue breastfeeding. For most common viral and bacterial infections, the illness is transmitted through respiratory droplets or contact with contaminated surfaces. The physical closeness of nursing is the primary route of transmission, not the milk itself. The parent’s body produces antibodies to fight the illness, and these specialized proteins are passed to the infant through the breast milk.
These antibodies offer the baby a form of passive immunity, which can either prevent them from becoming sick or reduce the severity of their symptoms if they do contract the illness. Studies suggest that breastfed babies may take longer to contract viruses like norovirus and rotavirus, demonstrating the milk’s protective effect.
A few specific infections warrant caution or temporary cessation of nursing due to a documented risk of transmission through milk. The human immunodeficiency virus (HIV) can be transmitted via breast milk, and nursing is avoided where safe alternatives are available. Similarly, human T-lymphotropic virus I (HTLV-I) and active, untreated tuberculosis are contraindications to nursing.
Cytomegalovirus (CMV), a common virus, can also be transmitted through milk, but the risk of severe illness is primarily confined to premature or low birth weight infants. For full-term infants, the infection is often mild or asymptomatic, and the benefits of nursing usually outweigh the small risk.
Physical Demands and Misinterpreted Symptoms
Beyond infection, the physiological workload of producing milk can generate symptoms that feel like sickness. Lactation is a physically taxing process that places significant caloric and hydration demands on the body. The lack of consistent, restorative sleep in the postpartum period compounds this exhaustion, leading to a feeling of being run down or unwell. Dehydration, a common issue, can manifest as headaches, dizziness, or profound fatigue, all of which can be mistaken for a viral illness.
The body uses a substantial amount of fluid to create milk, necessitating a significantly increased water intake. Prioritizing rest and proper nutrition is an important preventative measure against systemic symptoms. The physical discomforts of nursing, such as sore nipples, pain from engorgement, or back aches from positioning, also contribute to the overall feeling of physical vulnerability. Addressing these non-infectious, mechanical aspects of lactation, such as improving latch or ensuring adequate fluid intake, can often alleviate the general feeling of being “sick.”