CKD is a non-communicable illness that causes enduring abnormalities in kidney structure or function for at least 3 months [1].   CKD is a global public health concern that affects around 10% of the worldwide population [2]. This significant burden is only now being known and it remains incomplete. Unfortunately, the complex burden of CKD and expenses is constantly expanding, especially in low-income countries [2]. It will continue to increase as the prevalence of diabetes mellitus (DM), hypertension (HT) and an aging population increases [3].   In 2019, CKD was classified as the 7th leading cause of death worldwide, emphasizing the need for prevention efforts [4]. CKD is a significant issue worldwide in both developing and developed countries [5].   The Middle East area has a significant rate of CKD; the prevalence of CKD in the general population is 4.7% in Saudi Arabia [6], 6.8% in Jordan [7] and 14.9% in Iran [8].   In Europe, the overall prevalence of potential CKD in adult populations was estimated to be 10%, with two out of every three CKD patients going. This cohort had a high mortality rate, with CKD being the major cause of hospital visits and expenses [9].   HT, DM and obesity are major risk factors in the development of CKD and they are especially prevalent in Saudi Arabia [6,10]. Therefore, patient education regarding the importance of controlling high blood pressure and diabetes, the leading causes of CKD, can greatly improve kidney function and quality of life [11].   The considerable increase in the development of CKD to end-stage renal disease (ESKD) is expected to remain due to a lack of proactive measures to raise patients' understanding and awareness of CKD [12].   Prevention, early identification and effective treatment of the main risk factors of CKD, such as DM and HT, form an essential public health approach and are crucial in the Arab world, since these risk factors are widely prevalent [10]. Additionally, Lack of information on CKD, as well as unfavourable attitudes and behaviours, has contributed to a delayed identification of the disease [13].   One of the key goals of CKD management is to slow its progression to ESKD, thereby increasing lifespan and minimizing the need for dialysis or transplantation [1].   Research in developed and developing nations indicates a lack of public awareness of CKD and its risk factors [14]. In Saudi Arabia, many studies reported a lack of knowledge among the Saudi people about CKD [15-19]. Additionally, in Jordon, the public knowledge of CKD was intermediate [7].   Enhancing public awareness of CKD is necessary for implementing effective preventive programs. Individuals with early CKD or those at risk of developing CKD may be identified more quickly among communities with high levels of education and awareness regarding CKD [20,21].   The study aimed to explore the knowledge of kidney functions, risk factors, signs and preventive measures of CKD among the adult general population in Arar city, Northern Saudi Arabia.

Study Setting and Design A cross-sectional study design was conducted among an adult general population who are 18 years and older, both males and females, in Arar city, the capital of Northern Saudi Arabia, over the period from March 1 to September 30, 2024.   Sampling Tool A well-designed self-administered questionnaire, Arabic version prepared by reviewing the relevant literature [15,17,22,23]. The questionnaire was divided into six sections.   The first section included sociodemographic data The second section featured questions about renal function In the third portion, there were questions concerning risk factors for CKD The fourth domain asked about the signs and symptoms of CKD The fifth component includes questions regarding awareness of the conditions that necessitate screening The final part asked about preventative methods for CKD   The questionnaire was originally developed in English, then translated into Arabic and subsequently back into English by a multilingual expert. Two nephrology experts evaluated the content validity of the questionnaire.   A pilot study on 20 people was conducted to eliminate bias and technical concerns or any ambiguity in the questions or replies, before adoption.   Sampling Method Following ethical permission, a survey was conducted to recruit participants via an online questionnaire approach using several social media platforms (WhatsApp, Facebook). After describing the research objectives, participants provided informed consent, which was clearly stated at the top of the questionnaire.   Sample Size The minimum sample size was calculated according to the following formula:   N = (Z1−α/2) 2 P (1-P)/d2   = (1.96)2 X 0.50 X (0.5)/(0.05)2 = 383.4 ~ 384   Where (Z1−α/2) is the standard normal variate at 5% type 1 error (1.96); (P) is the expected proportion of awareness in Saudi Arabia (50%) and (d) is the absolute error (0.05). The sample was completed at 400.   Statistical Analysis The data was collected and then analysed using SPSS version 22. Categorical data were described as frequency and percentage, while numerical data were presented as mean and standard deviation.   Inclusion and Exclusion Criteria Adults who were at least 18 years old and willing to participate were included in the study, whereas those who were under 18 or refused to participate were excluded.

Table 1 depicts the sociodemographic features of the study sample. The study included 400 participants, with a mean age of 28.5±10.4. More than two-thirds were male (68.2%), more than sixty percent were single (64.5%), the majority were university-educated (70.3%), more than half were students (54.2%) and slightly less than half had a household income of more than 10,000 SAR. The prevalence of diabetes and hypertension was 15% and 17.8%, respectively.   Table 1: Demographic characteristics of the study participants Parameter No Percentage Age Mean ± SD= 28.5±10.4 Sex Male 273 68.2 Female 127 31.8 Marital status Single 258 64.5 Married 132 33 Divorced/Widowed 10 2.5 Educational level Primary school 19 4.8 Intermediate school 8 2 Secondary 54 13.5 University 281 70.3 Post-graduation study 38 9.4 Occupation Student 217 54.2 Employee 124 31 Retired 20 5 Others 39 9.8 Family income Less than 5000 SR 81 20.2 5000-10000 SR 131 32.8 More than 10000 SR 188 47 Suffered from diabetes mellitus Yes 60 15 No 340 85 Suffered from Hypertension Yes 71 17.8 No 329 82.2   Table 2 shows how the investigated population perceives kidney function. The most often reported kidney function was blood cleansing (84.4%), followed by blood waste filtering (76.3%), electrolyte balancing (73.3%), urine production (69%), hormone release (61%), protein breakdown (50.8%) and fat disintegration (47.5%). Urinalysis was the most often indicated renal function test (76%), followed by blood testing (67.8%) and blood pressure monitoring (62%).   Table 2: Perception of kidney function among the studied population Parameter No Percentage Clean blood Yes 339 84.8 No 34 8.4 I do not know 27 6.8 Help filter waste from the blood Yes 305 76.3 No 42 10.5 I do not know 53 13.2 Regulate body water and minerals in the blood, such as sodium, potassium, phosphorus and calcium Yes 293 73.3 No 38 9.5 I do not know 69 17.2 The kidney's function is to make urine Yes 276 69 No 78 19.5 I do not know 46 11.5 Releases hormones into the blood to regulate blood pressure, produce red blood cells and promote strong bones Yes 244 61 No 56 14 I do not know 100 25 Break down protein inside the body Yes 203 50.8 No 96 24 I do not know 101 25.2 Break down food to produce substances that dissolve fats Yes 190 47.5 No 95 23.8 I do not know 115 28.7 The most common kidney function test is Urinalysis Yes 304 76 No 33 8.3 I do not know 63 15.7 Blood test Yes 271 67.8 No 49 12.2 I do not know 80 20 Blood pressure monitoring Yes 248 62 No 58 14.5 I do not know 94 23.5   Table 3 shows the respondents' knowledge of renal risk factors. HT and excessive salt consumption were mentioned the most (71%), followed by DM (69.3%), obesity (65.8%), hereditary (64.3%), stress (60.8%), hyperlipidaemia (59%), heart disease (58%), insufficient sleep (53.8%), anaemia (53.3%), dye injection (51.5%) and female gender (48.3%).   Table 3: Knowledge of the common risk factors for CKD Parameter No Percentage High blood pressure Yes 284 71 No 28 7 I do not know 88 22 Excessive salt intake Yes 286 71.5 No 29 7.3 I do not know 85 21.2 Diabetes mellitus Yes 277 69.3 No 43 10.7 I do not know 80 20 Obesity Yes 263 65.8 No 52 13 I do not know 85 21.2 Hereditary factors Yes 257 64.3 No 50 12.5 I do not know 93 23.2 Excessive stress Yes 243 60.8 No 45 11.2 I do not know 112 28 Hyperlipidemia Yes 236 59 No 54 13.5 I do not know 110 27.5 Heart diseases Yes 232 58 No 47 11.8 I do not know 121 30.2 Insufficient sleep Yes 215 53.8 No 63 15.8 I do not know 122 30.4 Anemia Yes 213 53.3 No 55 13.7 I do not know 132 33 Dye injection Yes 206 51.5 No 65 16.3 I do not know 129 32.3 Being female Yes 193 48.3 No 72 18 I do not know 135 33.7   Table 4 displays the participants' perspectives on CKD symptoms. Water retention was the most often reported symptom of CKD (72.3%), followed by chronic fatigue (59.8%), nausea and vomiting (56.5%), thirst (55%), back pain (53.8%), fever (52.3%), frothy urine (51.5%) and symptomless (48.5%).   Table 4: Perceptions of symptoms of CKD Parameter No Percentage Water retention Yes 289 72.3 No 39 9.7 I do not know 72 18 Chronic fatigue Yes 239 59.8 No 47 11.8 I do not know 114 28.4 Nausea and vomiting Yes 226 56.5 No 47 11.8 I do not know 127 31.7 Frequent Thirst Yes 220 55 No 52 13 I do not know 128 32 Back pain Yes 215 53.8 No 59 14.8 I do not know 126 31.4 Fever Yes 209 52.3 No 62 15.5 I do not know 129 32.2 Frothy urine Yes 206 51.5 No 55 13.8 I do not know 139 34.7 Loss of appetite Yes 203 50.8 No 57 14.2 I do not know 140 35 Symptomless Yes 194 48.5 No 68 17.0 I do not know 138 34.5   Table 5 shows the participants' knowledge of chronic renal disease. CKD is defined by slightly less than 60% (58%) of participants as a reduced kidney's capacity to eliminate waste from the blood. More than half (54.5%) reported renal inflammation, while kidney stones and infection were reported by 45.5% and 43.5%, respectively.   Table 5: Knowledge of CKD and situations that require screening. Parameter No Percentage Reduction in the kidneys' ability to remove waste from the blood Yes 232 58 No 66 16.5 I do not know 102 25.5 Inflammation of the kidney Yes 218 54.5 No 79 19.8 I do not know 103 25.7 A stone in the kidneys Yes 182 45.5 No 127 31.8 I do not know 91 22.7 An infection of the kidneys Yes 174 43.5 No 95 23.8 I do not know 131 32.7 In your opinion, which of the following conditions requires screening for CKD Hypertension Yes 260 65 No 34 8.5 I do not know 106 26.5 Diabetes mellitus Yes 259 64.8 No 49 12.2 I do not know 92 23 A person with a family history of renal disease Yes 238 59.5 No 53 13.3 I do not know 109 27.2 A person needs at least one healthy kidney to lead a healthy life. Yes 286 71.5 No 47 11.8 I do not know 67 16.7 A person can live with less than one healthy kidney. Yes 171 42.8 No 117 29.2 I do not know 112 28   More than 60% of participants reported that hypertensive and diabetic patients require renal function testing, while roughly 60% mentioned that individuals had a family history of kidney illness. More than two-thirds agreed that a person can survive with only one kidney, while slightly more than forty percent said that a person can live with less than one.   Table 6 illustrates the participants' knowledge of CKD preventive factors. The most frequently cited preventive factor for the development of CKD was Staying fit and active (72.8%), followed by maintaining proper blood pressure (70.3%), eating healthy food and maintaining body weight (69.8%), having enough fluid intake (69.8%), maintaining blood glucose levels (64.3%) and reduced protein consumption (54%),   Unfortunately, fewer than half of the participants (43.8%) agreed that CKD is irreversible, almost 60 percent felt that kidney functions are diminished by old age and the majority claimed that CKD is serious.   Table 6: Knowledge of preventive factors of CKD Parameter No Percentage Do you think that the following can prevent CKD? Keeping fit and active Yes 291 72.8 No 27 6.8 I do not know 82 20.4 Keeping blood pressure controlled Yes 281 70.3 No 27 6.7 I do not know 92 23 Eating healthy food and keeping body weight Yes 279 69.8 No 35 8.8 I do not know 86 21.4 Maintaining enough fluid intake Yes 279 69.8 No 34 8.5 I do not know 87 21.7 Keeping blood glucose controlled Yes 257 64.3 No 44 11 I do not know 99 24.7 Decreased protein intake Yes 216 54 No 56 14 I do not know 128 32 CKD is an irreversible illness. Yes 175 43.8 No 90 22.5 I do not know 135 33.7 Becoming old will decrease the function of the kidneys. Yes 241 60.3 No 56 14 I do not know 103 25.7 CKD is a serious disease. Yes 299 74.8 No 37 9.2 I do not know 64 16

CKD is a growing global health crisis affecting millions of individuals worldwide. This progressive condition is characterized by a gradual loss of kidney function, which can lead to severe complications, including kidney failure and an increased risk of cardiovascular disease. Factors such as diabetes, hypertension and an ageing population contribute significantly to the rising prevalence of CKD. Awareness and understanding of various aspects of this disease would help address its root causes and implement effective management strategies with interventions and lifestyle changes to work towards alleviating the burden of CKD on communities around the globe.   The mean age of participants in the study is 28.5±10.4, very similar to the study of Alhowaish et al. in Riyadh [24]. while it was 37.15 ±16.24 in the survey by Younes et al. from Lebanon [25].   Regarding the participants' knowledge of kidney functions, the study revealed that the majority correctly answered blood cleaning, blood waste filtering, electrolyte balancing and urine production. In line with comparable research in Saudi Arabia, 93.8% [16], (87.9%), [26] 79.8% [15], 76.4%, [22] and (73.6%) [19] of participants believed that the kidney's primary role is to purify blood. In a Jordanian study [7], 92.8% confirmed that the kidneys purify the blood of poisons and transform waste products into urine. The awareness of the kidneys' filtering waste from blood was 79.4% in a study by Chow et al. in Singapore [27].   Regarding the knowledge of kidney function tests, more than 60% percent correctly stated urine analysis, blood testing and blood pressure measurement. Screening for CKD and frequent monitoring of renal function are critical public health strategies for preventing CKD from progressing into more serious stages. The patients' awareness of the regularly used tests to measure their kidney condition is vital in developing and executing health programs to meet the rising public health problem of the increased prevalence of CKD with advanced stages.   In comparable research in Saudi Arabia, more than 80% of participants correctly stated blood and urine tests as screening methods for renal function and 56.6% stated blood pressure measurement [15]. Moreover, in Abha, Saudi Arabia, urine test, blood test and blood pressure monitoring were listed by 89.7%, 90.3% and 53.5% respectively [28]. Research [14] among the Australian population found that around 65% of respondents recognized that blood and urine tests can be used to detect kidney function and just 20.3% knew that blood pressure assessment.   In terms of CKD risk factors knowledge, most respondents highlighted hypertension, excessive salt consumption, diabetes, obesity and inherited factors. The main causes of CKD are diabetes and hypertension. Investigating whether this misinformation is linked to the causes of CKD warrants further research. There is good evidence to support the efficacy of such a strategy in managing blood pressure and improving disease outcomes. An accurate and prioritized understanding of CKD risk factors promotes disease awareness and facilitates timely screening.   In industrialized and many developing nations, substantial numbers of individuals are ignorant of the two primary causes of chronic kidney disease: hypertension and diabetes [29]. In a study [18] done in Riyadh, Saudi Arabia, more than half (56.6%) of the participants showed an appropriate awareness of CKD risk factors. According to Almutary's study [30] in Saudi Arabia, DM and HT are the primary causes of chronic kidney disease. Research in Madina, Saudi Arabia [16], indicated that 65.8%, 52.4%, 49.7%, 43.9% and of respondents identified genetic factors, DM, obesity and HT as risk factors for CKD, respectively. Research conducted by Alobaidi et al. [15] revealed that 69.2% reported hypertension and 54.3% diabetes as risk factors for CKD. A study carried out in western Saudi Arabia [31] showed that 52.7% of participants considered diabetes as a risk factor for CKD. Ahmed et al. [20] found that 90% of the Saudi population identified obesity as a risk factor for CKD, 56% excessive salt intake and 60% reported DM and hypertension. Al-Husayni et al. [17] in Jeddah, Saudi Arabia, discovered that around 50% and 35% of participants were aware that diabetes and hypertension are risk factors for CKD.   In a survey in Hong Kong [32], most respondents (79.5%) identified higher dietary salt as a risk factor for CKD, while fewer than half recognized hypertension (43.8%), diabetes (44%) and hereditary factors (42.8%). A survey of the Australian population [14] found that 60.6% of respondents listed diabetes as a risk factor for CKD.   In terms of CKD symptoms, urine retention was the most reported, followed by chronic fatigue and nausea/vomiting. Furthermore, slightly less than half believed that CKD may be asymptomatic. According to a comparable local survey [15], 79.8% 68.8% and 44.7% of participants identified water retention, chronic fatigue and nausea/vomiting as signs of CKD, respectively. Furthermore, 70.9% of respondents in South Saudi Arabia thought that water retention is a sign of CKD [22]. In southern Saudi Arabia, 61.6% and 43% of participants in a similar survey listed chronic fatigue and no symptoms [23]. Alobaidi et al. [28], in western Saudi Arabia, 85.9% and 61.6% of participants identified water retention and fatigue as signs of CKD, while only 30% correctly recognized nausea, vomiting and lack of appetite. In a study conducted by Almutary [30], 70% of the participants correctly identified fatigue and nausea/vomiting as signs of CKD, while 70% did not know that the disease could be asymptomatic.

A substantial proportion of the participants were aware of the kidney functions, renal function tests and common risk/preventive factors for CKD. Less than sixty percent of respondents listed the most common symptoms of CKD. More research is needed to investigate the reasons for low symptom awareness and design a focused intervention to raise CKD awareness among the public.   Limitations Several study limitations should be noted before interpreting the findings. We conducted an internet-based cross-sectional study using a questionnaire distributed through social media sites, which may have introduced selection bias. Furthermore, our study sample is not representative of the broader Saudi population, which limits the generalizability of the research findings.   Ethical Statement The study was approved by the local bioethical committee of Northern Border University (HAP-09-A43) with decision no. (28/24/H) on March 18, 2024.