Findings
Blood emerged as the bodily element through which ‘high blood’ (which is how patients refer to hypertension) is experienced and made a reality for patients, and changes in the blood were seen as the mechanism through which hypertension is understood to operate in the body. In other words, blood is central to the ‘folk physiology’ of hypertension for many of our participants.
The centrality of blood is evidenced by the participants’ illness semantics. Aside from the term ‘high blood’, its literal Tagalog translation ‘mataas ang dugo’ or ‘malakas ang dugo’ (strong blood’) were also used to refer to hypertension. It was seen conceptually as one pole on a spectrum of blood states—the opposite of which is ‘low blood’ or its literal equivalent ‘mababa ang dugo’ (which conflates hypotension or low blood pressure and anaemia). Low blood features symptoms like dizziness and weakness, as Lorena, a-44-year-old female driver employed in a school transport services from Valenzuela described:
Aside from high blood, I also had low blood…my blood pressure was low and I was always dizzy. So I ate talbos ng kamote (a leafy vegetable with a red dye), and the low blood only lasted for a while.
The centrality of blood is also reflected in the way ‘high blood’ was understood to affect the body. Hypertension exists for many of the participants because of changes in the blood, particularly, in its perceived viscosity and temperature. In terms of viscosity, blood can either be malabnaw (thin or watery) or malapot (thick or viscous), with the latter state being associated with ‘high blood’ and the former with ‘low blood’. ‘Thick blood’ can lead to various symptoms, like headache and a thickening of the neck. In the long term, thick blood is also viewed to cause clogging of the blood vessels, as Fernando, a 64-year-old farmer from Quezon, explains, ‘the blood goes up because of the litid (vessels) are nababara (clogged) so the blood cannot flow.’ In terms of temperature, blood that is mainit (hot) or kumukulo (boiling) is likewise linked to high blood pressure—as will be discussed in the ensuing presentation of findings.
Blood and changes in blood were central to four main, overlapping causes for hypertension identified by study participants—all fairly similar in terms of frequency of mentions:
Namamana (‘Inherited’)—The predisposition for having hypertension is inherited, and that this genetic component is ‘nasa dugo’ (in the blood).
Init (Heat)—Hot weather or init (heat) can trigger episodes of hypertension by causing blood to heat up or boil.
‘Stress’—Physical and emotional stressors can lead to hypertension likewise by causing blood to heat up.
Pagkain (Diet)—Particular foods (and beverages) cause hypertension by making blood thicker and more malambot (viscous).
We now discuss each of these perceived causes, which are summarised, and their relationships illustrated, in figure 1.
Figure 1Folk physiology of hypertension.
‘Namamana’: folk genetics
Many study participants viewed hypertension as ‘namamana’ or inherited through blood. Some viewed deaths among family members due to stroke or ‘atake sa puso’ (heart attack) as meaning that they could suffer the same fate. This notion of genetic risk is evidenced by discourses around adherence to treatment and self-management.
Delilah, 42, female, a homemaker with a small livestock business in Quezon, provides an illustrative example. On the one hand, ‘she wasn’t shocked’ about having been diagnosed with hypertension because she knew the disease is in ‘in her blood’—but she was also apprehensive: ‘I was scared since my mother, father and other siblings had stroke. I don’t want that to happen to me as well’. Ultimately, she talked about how the hereditary nature of hypertension was a motivation to access health services:
Interviewer: What made you decide to get a treatment during that time?
Delilah: Since it runs in our family, I learned how to take BP and when the time came when I was getting high blood pressure results, I decided to go to the doctor to get professional advice.
This view is shared by Linda, 48, female, a community health worker in Valenzuela:
My mother already had high blood. And on my mother’s side…others (had a similar condition). I really thought about it. I said to myself ‘I don’t want that to happen to me, when I am older’.
These comments point to a perception of inherited predisposition to hypertension. There is also an underlying notion of this susceptibility being mediated by the blood. As Kristina, a housewife from Quezon, mentioned: high blood that is inherited is natural to the body, it’s unavoidable, it just arrives. It also points to an understanding of people having different types of blood depending in part with their family, which can influence the seriousness they attach to hypertension prevention, diagnosis, treatment and self-care.
‘It’s because of the heat’: Hypertension and temperature
Heat is also perceived as a trigger of hypertension—or more precisely, hypertensive episodes, especially among urban participants. As Ernesto (60, male, retired factory worker from Valenzuela) shared, this perception is also linked to changes in blood:
I don't know but maybe it’s because of the climate because it’s really so hot. It’s not like we’re living in an air-conditioned house. If it’s hot, your head also heats up, your blood boils, and so when they get your B.P., of course it’s high.
For her part, Rosita (58, female, a homemaker from Valenzuela) lists heat among three perceived causes, alongside exhaustion and fatty foods. As the conversation below shows, heat is seen as a risk factor, taken seriously to a point that it informs certain practices—although likely for several reasons other than fear of hypertension:
Rosita: Sometimes my BP goes down but because of fatigue and the heat, and it goes up again.
Interviewer: Is it really hot around here?
R: Very much… […] That’s why when we sleep at night all our windows are open.
I: That’s why you have a lot of electric fans here due to the heat.
R: Very much. It can kill you.
Views of heat as a trigger of hypertension can shape people’s behaviour, including self-management, with participants using fans or avoiding heat to try ‘lower’ their hypertension or maintain health. These ideas were apparent during fieldwork in the way participants organised space; multiple electric fans were commonly used during interviews and referred to by our participants as a way of addressing changes in hypertension status, in addition to their immediate function of alleviating discomfort, particularly in urban areas where the humidity and daytime highs of 32°C–35°C can be become overbearing in their small, tightly packed and poorly ventilated houses.
These temperature-related ‘care’ practices were adapted to work within the constraints of people’s livelihood and everyday work, as Cora, 62, a female farmer from Quezon Province shared:
Lucia, my friend, told me not to stay long under the sun because my (blood) pressure might go up. My job is farming so I’m always under the sun. If I cannot bear the heat, I go under a shade. I also wear a hat as a protection from heat.
The link between heat and hypertension supports participants’ view of blood as a dynamic state that can ‘boil’—but can also cool down, depending on the weather (as in the case of Ernesto above). This is also illustrated by Nerissa (female, a 54 year-old homemaker), a respondent from Quezon who owns a sari-sari store (neighbourhood store) outside her house:
Interviewer: How can you say you have high blood?
Nerissa: I feel dizzy especially when it’s hot. I get high blood for sure. But it subsides after a while.
Aside from signifying discomfort with high temperatures and humidity, heat also serves as a metaphor for anger and similar emotional states, as will be discussed in the following section.
Stress
Stress (which is also word commonly used in Tagalog) also figured in people’s perceived causes of particular episodes of hypertension and in their views on the type of self-management practices that would help address or manage it. These figurations of stress (both physical and emotional) are often linked to both heat and changes in blood, likely in both the metaphorical and experiential sense. As Ernesto said:
When you’re irritated, especially when it’s hot, your head will heat up. And your body will be affected. Your blood will boil. Then when they take your B.P., as expected going to be it’s high.
Barbara, 62, a female community health worker from Valenzeula, echoed the same sentiments, speaking of the following preventive measures:
If your blood is high, you should avoid thinking or getting angry….You shouldn’t think too much, it will make you tired, iinit ang ulo mo (literally: your head will heat up)
While Barbara emphasised emotional stress, Mariano (64, male, farmer) from rural Quezon, highlighted physical stress:
The tiredness as well (can lead to high blood). For instance, you had trip, you travel, you walk, then you work again. Obviously, your blood pressure will increase. But when you take a rest first, it will not, maybe. It will just be neutral.
However, not all strenuous activity is associated with stress leading to ‘high blood’; physical exercise was recognised as beneficial when done as a recreational activity—as opposed to work-related physical effort, further highlighting the role of emotions in this explanation. As this exchange between focus group participants in Valenzuela illustrates, this ‘healthy’ form of physical exertion is also articulated in terms of blood flow:
Participant 01: You have to move your body for the blood to flow. Exercise is a good way of getting tired. It’s healthy for the circulation because it releases toxins from the body.
Facilitator: But what about doing household chores?
Participant 02: That can be tiresome and stressful because you are doing and thinking at the same time for the whole day. It’s like a bad kind of exercise that can make you high blood. (laugher among the participants)
Diet
Most of the study participants say that their diet has contributed to their hypertension, particularly, their intake of foods they consider ‘unhealthy’ such as those that are maalat (salty) and mataba (fatty). Blood, once again, figures as the medium through which food exerts its effects on hypertension: participants speak of eating too much food, particularly those perceived to be high in cholesterol, as causing blood to be more malapot (viscous) and thus cause bara (clogs) in the blood, which, in turn leads to ‘high blood’ and the complications they attribute to it: stroke and heart attack. Cholesterol figures prominently in their accounts, but it must be noted that the local notion of ‘cholesterol’—understood simply as a substance that comes from taba (fat)—is not the same as its use in biomedicine.
This conversation with Mariano is illustrative of how cholesterol figures in their explanatory models:
Ah, eating foods with so much oils, people who likes fried food, meat (increases cholesterol).[…]I am guilty (of eating those foods) because I live alone. Because whenever I go farming in up in the mountains, it is easy to cook a whole chicken and I do not know that chicken has high cholesterol. It has cholesterol but I do not know if it’s high or not. I will just pack it and what I eat in the morning, I bring it in mountain. I consume all of it, obviously, my cholesterol will increase.
Particular notions of ‘cholesterol’ emerge from these accounts. For instance, cheap foods are seen by the participants as having higher cholesterol while their expensive ones are seen as healthier. This is highlighted in a conversation Aida, female, a 45-year-old homemaker and businesswoman from Valenzuela:
Consume only two eggs per day and it must be boiled. If you’ll eat fried egg, it has oil. You should only use olive oil. It does not contain cholesterol, right? It’s free of cholesterol, however, it’s expensive.
Another notion is that specific foods are particularly high in cholesterol—like crab and pork skin. In one of the research sites—a coastal community where crabs are affordable to low income households—one participant narrates:
If I eat crab, I start to feel that pain on the back of my neck. I avoid it because we must have a self-discipline and we are the only ones responsible for our treatment. So it’s up to us. You should just eat small portion and not large portion. All excess is not good even if you’re allowed to eat it
In the above, we see the immediacy of the food’s relationship to ‘high blood’; the fattiness or the perceived ‘cholesterol’ translates to symptomatology; it is perceived to have an immediate effect on the body. Conversely, the inability to eat adequately is linked to ‘low blood’.
As synthesised from various interviews and FGDs, some foods were also seen to make the blood malabnaw (thin)—and therefore be beneficial to hypertension—including fruits that are maasim (sour)—like citrus and green mango, as well as vegetables. On the other hand, foods like balut (fertilised duck egg), crabs, fatty meats (eg, roasted pork), gata (coconut milk) and alcoholic beverages such as beer were seen as malapot and are seen as beneficial to ‘low blood’ or anaemia. One generalisation gleaned from the food items mentioned is that sour foods and beverages appear to be linked to thinning the blood and lowering blood pressure, while those that are sweet and fatty are perceived to do the opposite.
These local notions also influence their self-care practices, as seen in this discussion with Pacito, a 39-year-old fisherman from Quezon:
Pacito: As what people say here, when you have high blood, you have malapot na dugo (viscous blood).
Interviewer: What happens when you have malapot na dugo [viscous blood]?
P: When you eat too much fatty and oily foods that can get stuck in your body and (can have bad effect to) your blood circulation. That’s why I stopped my maintenance (regular medicine for hypertension) and I drink kalamansi juice because they say that can make your blood thinner and I’ve mentioned before that I think my medication has side-effects to my throat. I didn’t like it. Sometimes when I’m fishing, we bring food there and condiments. I drink vinegar if it happens I get high blood out at sea.